Doesn't Android provide a license verification service, much like the recently discussed iTunes receipt validation process? I have an app, GPS Aids, which checks online if my license is valid. Again, this can be blamed on the developers, for not taking any reasonable steps to prevent piracy. If the app has to be cracked, it's going to reduce the piracy rate quite a bit.

As an aside.. I would never pirate a $1 app, that is just ridiculous. I've spent way more than the average person in the app stores.