Angry bird's install base definitely gives them a leg up on cross-app promotion. With so many users they can push them to each of their new apps. And they have

Angry bird's install base definitely gives them a leg up on cross-app promotion. With so many users they can push them to each of their new apps. And they have a ton of revenue to re-invest in advertising/app development. However, I wouldn't say "Angry Birds" is going to remain king. Another game can very well dethrone them. Nothing's a guarantee when Apple can change the rules of the game for the App Store.