Yes, but as this article and many others have discussed; that number is shrinking. Gamers still exists, but you don't make billions of gamers. You make billions of consumers as a whole, and convincing people to buy yet another piece of hardware to do something is a hard sell. "I could just use this thing I carry with me everywhere," or, "I could buy a 2nd dedicated device that only does games (well)"

I'm aware the DS/3DS/etc do more than games, but anyone that uses the DS browser and thinks it's good is a liar.