It depends on the site. Cake charges 7% on their DoN's. And yes, 60% cashing is profitable, and while there are definitely ways to improve that-in the 10 dollar games a good player might be able to hit 70-75% I think, any profit over a long term is strong.
I think I'm just over 50% and not beating the rake so far, but that's because I'm still figuring out bubble play in these.