ailon's DevBlog: Development related stuff in my life

CPA, CPC, CPI… it’s all a big lie

8/21/2013 5:29:00 PM


It’s an advertiser driven market out there. Meaning that there’s more ad space on the web and in mobile than there are ads to fill it. And what were advertisers always dreaming of? They only want to pay for results. So when someone advertises a product they want to pay only when someone buys it. If you have an app, you only want to pay for the downloads. A service? Pay for subscribers. And so on and so forth. Worst case acceptable scenario – pay for clicks. At least they’ve acted on my ad! We finally have a way to track these things. I’d argue that we tend to give that tracking thing too much credit, but that’s another story.

But if you look at the other side of the fence, publishers, ad networks, developers never think in CPC or CPI. They always think in CPM. Even if they have to agree to sell you on the CPI basis, they will always measure their own results in effective CPM. And even if they agree to your CPI rate on the first run, they will look at what eCPM it brings them and react accordingly.

What does it mean for you as an advertiser? Any reasonably smart bidding-based system (AdWords, Facebook, etc., etc.) doesn’t rank your campaign ads based on your CPC bid, but rather on the resulting eCPM. And “human-based” systems are pretty much the same. So, if your CPA campaign results in poor eCPM, they will either raise your rates or just refuse to continue dealing with you (in case you are beyond saving threshold). On the other hand, if the publisher is happy, it most likely means that you are overpaying for the service. Even when they are desperate and don’t kick you out despite poor performance of your campaign, it’s likely you’d get an even better rate on the CPM basis.

So what I’m getting at? Any product has a minimum reasonable price. In this case the product is ad space and the price is measured in CPM whether you want it or not. So the only way for you to control the destiny and the price of your campaign is to buy it on the CPM basis too. In this case it will be you who evaluates the effectiveness of an advertising platform. Yes, it may cost you more for the test run, but after that you know your metrics. You may find out that you are paying a lower CPA than you were planning too. And even if results aren’t satisfactory, you can negotiate better rate in terms that are clear to the other side. Or you can just decide that this is not the right platform for you and focus your precious time and energy on those that work.

In any case, buying on the CPM basis you control your advertising, buying on the CPA you only control your advertising expenses.

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Could this be the first Google Glass game?

5/7/2013 2:20:50 PM

I’m not sure if Google Glass already has specialized games or not, but a game my friend has just released – The Howler – has got me thinking. Check out this short video demo and decide for yourself.

Yes, you will look like a complete dork from the side, but aren’t people getting Google Glass going for that dork look anyway? Even the International League of Anger Managers recommends it.

Anyway… Even if not for Google Glass this game looks fantastic – it features amazing art based on the sights of my hometown of Vilnius, Lithuania with that darkish steampunk(?) look. And the craziest thing is that all of this art was made by the artist who has probably never used a PC. All of these beautiful images were hand drawn on paper. I can imagine the originals going on my wall, but I guess I won’t be able to afford them once this game becomes a cult item.

Check it out:




The gameplay is casual and fun. Your goal is to pick up and deliver a package using an air balloon or some other contortion, which you control by either touch or voice. You have to consider wind currents and other obstacles. And you can blow them up just by screaming “UGGH!!!”. It’s a fun and sometimes challenging game, but even if you are not into this kind of game it’s worth getting just for the crazy awesome and unconventional art.

Available on iOS and Android (via Amazon).


Microsoft Should Promote an iOS Game

2/7/2013 5:09:26 PM

Angry Birds came to Windows Phone a year late (or something), Instagram is still not there, etc.. It doesn’t matter that there are other alternatives, it’s a status, validation thing. iPhone and now Android users always looked down on us, Windows Phone users, and bragged that they have the Hip App X, but we don’t and that they had the Fun Game Y 3 months before we got it.

But guess what? Things are changing. Even if slowly. A few weeks ago I had an experience at a semi-drunk party where people came up with an idea of having their faces “ugglified” by some real time phone app and the app in question was CamWow. Surprisingly (or probably not) it worked better on my Lumia 920 than iPhone 4s and 5. I’m not sure what was better, but my iFriends wanted to look ugly on my phone rather than theirs. And another friend with Galaxy S3 was sitting silently in the corner. There’s no CamWow for Android. Now I’m pretty sure there are other similar apps on Android, quite possibly they are even better. But you know what? There are other photo editing apps on WP, some even better than Instagram, but Instagram is a status thing and I get it.

There are also quite a few physics games on Windows Phone. At least one of them is better than Angry Birds, in my humble opinion. The game is called Krashlander and it has been available on Windows Phone since day 1. Now – 2 years 3 months and some days later – it makes it’s debut on iOS and our iPhone friends can finally enjoy what we have finished 2 years ago. Good for them! Go get it.

I think Microsoft should make a bold move and promote Krashlander for iOS. I’m sure this will never happen, but a TV ad saying something like “The Windows Phone hit game comes to your iPad, finally.” would be very cool and show that times are changing.

In any case go get Krashlander on iOS or Windows Phone (if you managed to miss it somehow) and you are welcome.

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Public App Feedback #1: Nextgen Reader for Windows 8

1/29/2013 6:03:22 PM

I’m going to try something new. There are quite a few apps that I use very often and like a lot, but obviously I have a few things I don’t like about them or some minor things I miss. I was meaning to send feedback to developers of these apps for a long time, but couldn’t find the time/willpower.

At the same time I promised myself to blog [almost] daily. So I thought I can shoot 2 of these goals with one shot. Hopefully this feedback is valuable not only to the developers of said app, but other developers too. If not, just let me know in the comments below and I’ll consider shutting down this new “section” of this blog.

To be clear, I’m only doing this for great apps that I really like, so you can consider these feedback posts as my endorsements of the apps. I have no interest in providing feedback for crappy apps (well, unless I have some special feelings towards the developer ;)

Nextgen Reader for Windows 8/RT

The first app in this series is Nextgen Reader – an RSS reader (Google Reader client). I’ve tried quite a few of the feed readers. Some of them were more “powerful” than Nextgen Reader, some offered more “innovative” approach to reading RSS feeds, but I prefer the straightforward approach of Nextgen Reader.

That said I had a love/hate relationship with the app for some time because it wasn’t very stable a couple of minor versions ago. At some point it was crashing too much and I thought I had enough. So I switched to Feed Reader which is another great reader even though I don’t like the UI all that much.

It seems that after an update a couple of weeks ago Nextgen Reader stopped crashing (at least didn’t crash on me yet), so I’m back to using it as my primary reader and here are things I don’t like or miss…

Do we need 2 modes?

Screenshot (6)Screenshot (7)

One of the “killer” features of Nextgen Reader is support for 2 modes: “classic” which is close to Google Reader or Mail app or something you would expect a feed reader to look like (left); and “modern” which looks like People and other Windows Store apps with large panels for each feed item.

I assume the first is aimed at keyboard-mouse users and the second one at touch users? Honestly I don’t know which one I prefer. And most importantly I don’t hate any one of them. I could’ve used one or the other just fine. The presence of 2 modes just adds confusion and wastes my brain cells when I think about switching (or not switching) to the modern mode on every launch. I’m pretty sure it also wastes precious developer time. But I guess there are people who feel strongly in favor (or against) one or the other. So dropping one of them now could result in a public outcry.

At the very least there should be an option to pick the mode it launches in. Or better yet just persist the mode between launches.

OneNote-like collapsing of hierarchy

Another annoying thing is that in classic mode all 3 columns (feed list, feed post list and content) are always visible. This is not a big deal when used in full screen mode, but I mostly have a Tweetro snapped to the side when reading feeds and all 3 columns suffer:

Screenshot (8)

I really don’t need to see the feed list column when I’m reading 20 articles in a particular feed. The list should be collapsed. Most of the other RSS reader apps do this. Even craptastic Mail app does it. And OneNote does it beautifully.

Wider reading pane in “filled” mode

Hierarchy collapsing would allow for content pane to be wider in classic mode and there’s no reason for reading pane to be as narrow in filled mode as it currently is.

Screenshot (9)

Just make it wider.

“Open in browser” is behind ellipsis in “classic” mode

When I read a post and want to read the comments or post my own I’d like to go to the website in a browser. In “modern” mode the “open in browser” button is front and center (top left, actually ;) (see the screenshot above). For some reason in “classic” mode the “open in browser feature is hidden behind an ellipsis

Screenshot (11)

There’s more space in that top bar to fit it even in the filled mode. And I sync once per reading session and wouldn’t mind going to that sub menu or app bar to do that, but I’d love to be able to open the post in browser without that extra tap.

Video resizing

New version resizes images to fit the reading pane. That’s great. It would be great to do the same for videos (at least YouTube) and I think it’s pretty easy to do.

Screenshot (13)

Part of the video doesn’t fit and YouTube’s HTML5 player craps out a little when it doesn’t fit into the screen.

Sync doesn’t load feeds that had no posts

And finally a minor bug report. It seems that after you’ve read all the posts in a feed syncing doesn’t load new posts for that feed.


That’s it. As you can see most of my issues are pretty minor and otherwise Nextgen Reader is an awesome app. Highly recommended.

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1/7/2013 8:04:53 PM


I’ve recently switched my personal email account from Gmail to I’ve been using for several weeks now and I really like it. I’ll need some time to figure out if it’s really great or was I just wowed by its slickness. On the surface it feels nicer, faster, more natural when navigated with keyboard, etc. But that’s another story.

This post is about one “feature” that made its way from Hotmail to It’s the thing I hated the most in Hotmail. I complained to support about it like 3-4 years ago and got a response that, no, it’s not possible to switch this feature off. It’s been several years since then, a new UI, a new domain, a new name but this ridiculous feature is still there and you still can’t turn it off.

That feature is a popup (you can see it at the bottom of the screenshot above) offering you to collect your emails from another account into your The email address in question is the one I use as my Microsoft Account (formerly know as Live ID). It’s not a or or address. There’s no real mail box behind it so I can’t set it up to make this dialog shut up. And even if I could, what if I just don’t want to?

You can close this dialog, but the next time you visit it will pop up again. How difficult could it be to make a way to disable this “feature” permanently? I don’t have any hope of getting it fixed via official support channels so the only thing left is bitching on the internet. So here you go, I’ve bitched. I can now return to the regular things. Right after I click that “Close” button and swear.


AdDuplex Gift Coupons for Your Developer Friends

12/19/2012 2:49:38 PM


Do you have Windows Phone or Windows 8 developer friends? One of the best holiday gifts you can give them is some extra exposure for their apps. That’s what AdDuplex gift coupons are fore.

There are 3 types of coupons:

  • $15/5,000 impressions
  • $50/20,000 impressions (list value $60)
  • $100/20,000 impressions (list value $200)

That’s an easy and valuable present for your geek friends.

Buy AdDuplex gift codes here.

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Shifts Calendar apps for Windows Phone

12/18/2012 7:34:54 PM

My wife works in shifts. Randomly distributed over a month. Every month she gets a sheet of paper with a list of shifts in a table with other people. What I usually did was take a picture of that list and then look through it trying to figure out her schedule for today/tomorrow. This isn’t difficult but pretty inconvenient. So for a month or so I was musing about doing a personal hackathon to make an up to do that more conveniently.

Does your idea pass a “Google test”?

Well, this app was never meant to be a business, because I always thought it’s too niche. That’s why I never thought it could exist and never bothered to search for an app like this. But as they say “there’s an app for that”. Even for something you think only you and 2 other people need. So I finally stopped procrastinating and did a search for “shifts calendar”


The funny thing is that I either didn’t find SaTurnos when I did the search on the phone or missed it because the name and tile didn’t catch my eye. So I’ll only cover the remaining 3 in this post.

My requirements

I had 2 must-have requirements:

  1. easy to enter shifts – I don’t want to spend half an hour to enter the shifts.
  2. live tile – I want it to be easier to check the shift with this app than to look it up in the photo, way easier.

There are a few things that would be nice-to-have but I can live without them, namely

  • export to [real] calendar
  • share the data file with other copies of the app (wife’s, daughter’s, etc.)

Choosing an app

shiftscalendarHere’s a brief look at my thought process when choosing one of the 3 apps.

First of all only one of the 3 apps had trial – ShiftCalendar

Since it was only one of the 3 that had a trial it was an obvious choice to try first without even going through description or reviews. Glance at the screenshots and instant download. At this point, if it satisfied my requirements it would be over for the other 2. Can’t understand why would anyone decide not to do a trial or a free version with upsell/IAP/ads.

Anyway. Unfortunately 2 other apps got a chance because ShiftCalendar failed both of my requirements. Entering shifts is relatively painful – for every day it opens a windows to select a shift. You can select multiple dates for the same shift and then set it. Still a little suboptimal, imho. Moreover it only lets you pick a color for the shifts so you end up with a colorful calendar where you have to remember which shift each color represents. Probably easy after a few days of use, but still an odd decision. And no live tile.

So, as I said, only the fact that it didn’t satisfy my requirements gave the other 2 a chance. Since they didn’t have trial I had to read their descriptions and reviews relatively carefully.

shiftworkcalendarFirst was Shift Work Calendar. The screenshots looked nice and feature list impressive. The app has way more than I need, even though it doesn’t have any of my nice-to-have features. That said it has an export to image feature which on one hand is better looking and easier to digest and share than the original sheet of paper, but on the other hand screenshot feature on Windows Phone 8 basically renders this a non-feature.

So the calendar looks nice, entering shifts is easy (even though I envisioned a better input UI for my imaginary app) and live tile is listed and showcased on one of the screenshots.

With everything looking pretty good one “feature” threw me off completely and made me buy the other app first and I only bought Shift Work Calendar after I decided to do this review.

That “feature” is:

30 page user guide downloadable from the help page.


Seriously! This is the reason I chose the other app. That and the fact that some people in the reviews mentioned this “feature” as something you would need to figure out how to use this app. And I actually had to reread the description (managed to do without the user guide) to get a hint on how to get the life tile to work since it didn’t work on the main tile (you need to go to calendars, select a calendar you want to pin and press the edit button (pencil) and there you’ll find a button to pin it).

The tile looks a little washed out (probably due to the fact it was made for WVGA displays) but otherwise displays all the essential information – today’s shift on the front and tomorrow’s shift on the back.

shiftwerkSo this brings us to the third app and the first one I’ve bought – Shiftwerk. The app looks pretty good, even though I prefer the look of Shift Work Calendar. The data entry is pretty much identical to Shift Work Calendar and is fine with me. Like ShiftCalendar it only shows shifts via colors in the calendar, though. That said if you tap on the date you see the details under it. Another thing is that it always uses Sunday as the first day of the week and doesn’t pick it up from your regional settings and doesn’t have a setting to set the first day manually.

Live tile worked “right out of the box”, looked crisp and it didn’t require reading a 30 page manual ;) Unfortunately, though, there’s one major flaw with the live tile for me. It show the next shift. Meaning that if you work say from 2pm to 8pm today it will start showing tomorrows shift after 2pm. This is probably fine if you are the one working in shifts – you would probably know that you are at work at 3pm. But since I need it to know someone else’s shifts it doesn’t work for me. If 3pm was the first time I decided to check it I will have no idea if today was a day off, first shift or second shift. Not a super-major issue but still a minus in my book.

So it looks like I will be using Shift Work Calendar after all, but I’m keeping all of them pinned at least until the end of the month to see if I’ve missed something. Here’s how they look pinned:


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Ad Rotator (Gergely Orosz and Simon Jackson) on AppBizDev

10/15/2012 4:00:53 PM

If you monetize your Windows Phone (and Windows 8) apps with ads you probably know not to rely on a single ad network. Some do better in one region and have nothing to show in all others, some pay more in some countries but less in the others, etc. And the fill rate is never 100%. So to make sure you utilize your ad space to the max you use multiple ad providers.

It’s not too difficult to implement a system that will switch from one ad provider to some other when there’s no ad to show. But if you want to do it really well you’d probably need to have different defaults for different locales. And to make things more complicated performance of different ad networks changes regularly. So you don’t want to hard code any of these settings into your app and issue an update whenever market situation changes. You can still implement an intelligent system like that yourself, but why reinvent the wheel?

There’s an open source project called Ad Rotator which can do all of the above and more for you. We’ve interviewed lead contributors to the project – Gergely Orosz and Simon Jackson on the latest episode of AppBizDev podcast. Check it out and make sure you subscribe in Zune, iTunes or any other tool to get new episodes automatically.

And, btw, if you have some music skills in addition to your awesome dev skills, you can get a MILLION free ad impressions on AdDuplex network by contributing a theme music to the podcast. Check out more details here.

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Spotify-like App Stores

9/24/2012 3:03:52 PM

Photo by ZeroOne

I’m the last person to say good things about iTunes, but there’s no denying it brought legal digital music to mainstream users. Same goes for iOS App Store. Geeks were buying Windows Mobile apps long before the App Store, but Apple made it easy for a regular person to buy apps for their smartphones. That said, buying MP3s-to-own sounds very old school in 2012 and I bet only the most devoted fans or those who have never heard of Spotify, Zune Pass, Rhapsody, etc. still do it.

But what about apps? All of the app stores still operate in the “classic” iTunes model. Even though it’s clear that paid 99 cent app model never really took off on Android, all Windows Phone success stories are ad based, and even on iOS free-to-play games reign supreme at this stage.

Yet, I think it should be way easier (from the legal standpoint) to introduce the subscription model to the app stores than it was (is) in the music world. Obviously not every smartphone user would like to pay a monthly fee for the app firehose and not every niche app maker would agree to get pennies for each download/use. But, in general, the 99 cent developer crowd should be happy and power users would happily pay $5/month for unlimited access to most of the app catalog. And it shouldn’t be just one or the other.

There’s no doubt it would take a lot of math, market testing, etc. to perfect the formula, but overall I think it’s a win-win solution and an obvious next evolutionary step in the app store history.

What do you think?

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