The iOS/mac app store is a bit of a crapshoot from what I hear these days with developers either making very significant sums of money or not very much at all.

The iOS/mac app store is a bit of a crapshoot from what I hear these days with developers either making very significant sums of money or not very much at all. I'd expect the Windows store to be similar when it comes out. If you manage to get promoted on the front page or something similar, you'll get a huge amount of exposure which should translate into a huge number of sales. Microsoft's more or less going all in with it, and when they do that, within a couple of years they tend to get things right [or at least force them into tons of places] (xbox, azure, SharePoint, etc). The store's going to be on hundreds of millions of desktops and other devices, so while it may be a case of needing to convince people to sign up for the store, I think that it'll gain traction pretty quickly. WP7 apps supposedly do better on average, and though that's probably largely marketing hype, it's also likely related to the fact that there arent x hundred thousand apps on WP7. When Windows 8 hits, there won't be x hundred thousand apps in the store either, so there's a window where if you're ready to go, you'll have a decent advantage (though this will get slimmer with every day) even if only a small number of people (comparatively) sign up for the store. All in all, if you're quick to market, there's a bundle of cash to be made. If you take longer, the money's still there but it'll be riskier (and related to how promoted / lucky / app-store-SEOd you are). These are true whether or not the windows store is a flop - but considering the money that's in it for Microsoft, they'll be pushing it as hard as they can. If you really want to hedge your bets and your ideas are compatible, make it mostly web-based with a Metro front-end. If Metro does get pulled or locked down too much, then the real alternative will be a larger shift to the browser for applications imo. You can also more easily double dip at some point in the future and appeal to a broader audience while still getting the app store cash.