Android is (very) slowly starting to pick up. My apps have just started to bring a little more than $10k/month, from ads alone, while I have friends with million-dollar apps on the iPhone who haven't passed the $30k mark on the Android with the same PAID apps after a whole year.
On Android, you have to build trust, even a user base (if you're not Angry Birds) before launching a paid product. Quality must be top-notch from day one, and god-forbid your app doesn't work on one device and some upset user "rewards" you with a first 1 star-review. I've seen countless apps being pounded for small issues at launch.
Long story short, if you want to make money with Android, you need to have loads of patience :-)