This is the app story that all my Windows Phone friends talk about as "a success story". It's really "the success story", as it's the top downloaded free game (except for XBox Live Extras).<p>I wonder what the revenue numbers for the top free iPhone and Android games are? Tapitude looks like it's doing about $3,000 a week / $400-500 a day. (Am I reading their chart right?) Didn't we hear plenty of stories about how Draw Something was doing $100,000 a day (now that's probably combining ad revenue and in-app purchases from the free version plus the sales of the paid version).<p>I'm not saying that there isn't money to be made on Windows Phone, but if the top free game is only doing $400 / day, it's orders of magnitude less than on iOS. Is it worth it to have your app in the "smaller pond" of a less-crowded app store? Maybe.<p>I suspect their huge spike over the past 2-3 weeks is due to the Lumia 900 - everyone trying out some new apps on their new phone. Time will tell if this is the phone that really sells the public on Windows Phone, but it's clearly their best success yet (top selling phone on Amazon).