I'm trying a new strategy for serving ads in the free versions of my Android apps. Sales on Golf Solitaire slid way down after the first week, so I've released a free version using a "day pass" model, similar to the way Salon.com or some videos on Hulu work.
Basically, when you open the app for the first time, a dialog appears with an ad, explaining that you need to click on the ad to visit our sponsor's website. If you do that, then relaunch or reset the app, you can play the app ad-free for the next 24 hours. After that time period, you'll see the ad box again.
I decided to try this model because the old way I was serving up ads periodically throughout the game, and people were just closing the ad window more and more without visiting the ads. For the past two months, I'm serving between 150,000 and 250,000 ads per day, but only getting 100-200 click-throughs.
This strategy focuses on serving far fewer ads, but getting many more click-throughs. If the model works well with Golf Solitaire, I'll go ahead and apply it to Spades. I expect some complaints, but I think some users might actually prefer such a system. We'll see.
Implementing it was a pain, though. AdMob doesn't make it easy to detect whether one of their ads has been clicked, so I had to implement it in a pretty clumsy way to capture that an ad had been visited. I had asked for help in a couple of forums, but got no responses. Luckily I was able to figure it out on my own.
Updates on how well it works will be forthcoming.