Case studies are always fun. You can't necessarily extrapolate the information and say it will apply to all cases equally, but you can gain some inferences from such cases and look for trends across others.

In this instance, one app called 'Mortal Kombat Tactics' by Neuralnet was released both on Android and Windows Phone and offered for free. What's the difference in ad revenue? Here it is, broken down by one of the developers, Alex Perez:

Android (AdMob)

  • Day 1 - 1,866 Impressions / $0.57 Revenue
  • Day 2 - 497 Impressions / $0.27 Revenue
  • Day 3 - 521 Impressions / $0.05 Revenue
  • Day 4 - 496 Impressions / $0.25 Revenue
  • Day 5 - 304 Impressions / $0.13 Revenue

Giving us a grand total of 3,684 Impressions and $1.27 in Revenue

Windows Phone 7 (PubCenter)

  • Day 1 - 2,070 Impressions / $1.28 Revenue (already surpassed Android's 5 days)
  • Day 2 - 1,903 Impressions / $2.52 Revenue
  • Day 3 - 2,391 Impressions / $4.63 Revenue
  • Day 4 - 3,693 Impressions / $3.86 Revenue
  • Day 5 - 2,274 Impressions / $2.48 Revenue

Giving us a grand total of 12,331 Impressions and $14.77 in Revenue

What is revealing about those numbers is two-fold. For one, the Windows Phone app clearly has more visibility on the platform due to less competition. As a result, it receives more ad-impressions. Second, all else being equal, the revenue is much higher for Windows Phone than Android. In fact, overall ad revenue in this case is nearly 3x that of Android, which is quite impressive.

For the developer here, Neuralnet, Windows Phone is the clear winner, making their investment much more worth their time in development. [Funny side note, we bought the Xbox 360 Mortal Kombat game awhile ago and this was the first app we downloaded and used for the game--it's a nice app and clearly has the visibility it needs on our platform.] You can find it here in the Marketplace.