Speed Bones Lite[iTunes] is a game that helps students learn human anatomy. It has been relatively popular in the medical section of the App Store. It was made to promote the paid version Speed Bones MD[iTunes] and has been available in the app store since May 2009.
Google contacted me less than three months ago and suggested I put one of their banners in Speed Bones Lite as part of their Adsense for Mobile Applications beta program (This was before Google aquired AdMob). Normally I would not have had the necessary volume of downloads to meet the criteria for the beta program but they were specifically looking to put advertisements in medical applications and very few medical apps have high volume, the medical section being the least popular section of the App Store. The paid version of my app had a good run but because of new competition, it was starting to fall off the charts. I had nothing to lose by trying to get a little bit more revenues with Google ads.
At the time, I was getting about 600 to 700 downloads of Speed Bones Lite per day. I thought to myself that if I managed to make $5 a day on the ads, that's $150 per month, it would be worth my efforts. I submitted an update to the app store with the Google ads and since my expectations were low, I forgot about the whole thing.
A month later, after the ads had been running for almost two weeks, I decided to take a peak in my Adsense account.
I jumped a little when the overview page presented me with the following line:
Today's estimated earnings: $118.17
Now, I happened to log in on a day with above average earnings but since then the numbers have been consistently good. My free game is now making more than all of the pay versions (Bones, Muscles, Angiology, Anatomy) and on some days, more than all of these versions combined.
The number of page impressions is much higher than the number of downloads. This has been encouraging for me as it means people are not downloading and playing only once or twice. They are returning to it many times.
Clickthrough rate has averaged 2.6% since the beginning and the eCPM has been excellent, averaging 14$ during the period and surpassing $35 on one day.
I don't know if my success is atributable to Google's excellent targeting algorithm or maybe to the fact that players from the medical field are worth more per ad clicks than other gamers. All I can say is that, in certain conditions with certain populations, it is possible to make money with ads even for relatively low volume applications. Given the amount of money Google dished out for AdMob, I would bet that I am not the only developper profiting from ads.
If you like the Speed Anatomy series of apps please nominate Speed Bones MD
Also let Dan Grigsby know you like my app as he will help chose the official nominations.