There are a lot of different business models. Sell actual software/content. This is the easiest with Ovi, but the N900's lack of DRM does not encourage this model Sell subscription. If your software provides a service, you can sell that and DRM is not an issue any more. Sell support. Depends on actual software, obviously, not really applicable to trinkets. Ads. People dislike this, but hey, it's a business model. Donations. Not really a business model, but it IS income. These are basic ones, most models fall into these groups (or combinations of them).
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...