One Small Thing Google Could Do to Increase the Amount of Paid Apps Being Bought
Maybe this is a little too obvious, or maybe it won't make a big enough splash, but here it is:
"Gift cards". Or rather, prepaid cards, much like iTunes cards.
I personally don't have a credit card, being a teenager, which means I'm limited to free apps on my GNex. I could sideload, but I don't believe in piracy.
Compare that to my iPad, where I can buy prepaid gift cards with whatever cash I have at the time, and then buy premium apps (and in-app purchased, such as coins on DrawSomething or brushes in Paper).
It's not too difficult, and I personally would use them. I'm not sure how big of a dent it would make, but think of it this way:
Apple - Uses credit cards and gift cards. Very successful with paid apps.
Amazon - Uses credit cards and gift cards. Successful with Paid apps.
Google - Uses credit cards. Not successful.
Just a thought.