If you can write a game that can generate a million downloads, then you can probably do quite well on adware. 1000-50,000 are more realistic. Anyway, leaving this aside, you're still wrong: the security tools on decently configured PC's will pickup a naughty application being naughty in the first few days. After which the app will be removed from download sites, before it has time to spread.
You might say that the app could wait six months to build decent user numbers before doing naughty things, but a lot of people delete this things every couple of weeks or so.
Which is why the world economy isn't collapsing because of $50M videogame thefts, in case you were wondering. In the real world, investing serious effort in a free game would probably only yield a few hundred successful attacks.
You seem to be implying that maemo tools are poor? I can't comment.
So you're basing your personal security on Nokia's continued lack of success? I think the strategy will probably work, but as I said, personally I'd find it undignified.