Findability within the Market might also be a factor. A search for "swedish" in the App Store, and it's on the first screen. But it's quite a long scroll down on the Android Market.
This is the testament to the reach of the App Store. Your app is targeting an incredibly small, niche market, and you're still selling hundreds of copies.
Sounds like it was the primary reason you had low sales. Without similar placement in the Android Market, you really can't claim that one market was more successful than the other purely on its own merits.
I wish I knew where customers came from, but the app Store and Android Market are both black boxes.
I'm sure some people find apps from within the store (e.g. searching for "swedish") - but I expect most to come from youtube (where there are lots of GoSwedish videos) and then search for the app by name.
Update: Or maybe I just need to do more to get the word out. I sold 10 Android copies yesterday! (Thanks HN!)
Findability within the Market might also be a factor. A search for "swedish" in the App Store, and it's on the first screen. But it's quite a long scroll down on the Android Market.