Angry Adverts. Rovio launched the android version of Angry birds they did two new thing, one was use getjar.com (though that fell down in the demand) in addition to Android Market. The other was to make it free but have in app adverts. Optionally you’ll be able to pay to remove the advertising, which may be a motivation behind the terrible implementation of in app advertising. Instead of using the dwell screens, the ads are placed at the start of each level, when the user is concentrating on the level arrangement and not even looking at the ads, certainly not in any position to click and follow though as your at a start not natural break point.
If I was an advertiser I’d be livid.
Theres plenty of ways they could of made the adverts integrated. In the level end screen or the pause screens. Hey even make the pigs deliver the adverts for even greater eyeballs stick. Examples mocked up roughly below:

a little rejig to level end screen above.

or animate and include the pigs to deliver the adverts.