Based on simplicity, MP3 is the easiest to decode, lowest complexity. Followed by WMA and LC-AAC.

But battery life also depends on what program is playing the music file. Some programs are more efficient. Also depends on the encoder sometimes.

The obvious answer is MP3, BUT If it was that obvious, i don't think Zinga would've made us guess. Judging from Zinga's personality i doubt it's MP3. There has to be a catch. Probably something like a more complicated format being playable on a different program that uses less battery or something.

Also, DRM will kill the battery life, as it forces extra work. So if ur an idiot, and encode with DRM, then that'll probably take the most battery life.


hmmm... Since AAC is that much more complecated that MP3, i say it won't really be AAC.


Based on logic alone, i would lead towards MP3, BUT it's also likely that Zinga's not going to ask that question if it is... BUT MP3 is that much more simple than  LC-AAC... Dammit, i guess WMA.

If it really was MP3, then i'd be really pissed.