I tried it last year but hardly got any sales, may be CB tracking issues, but i get good resukts when i use promote CPA offers using media buys, testing and tweaking your campaign is key
I has some limited success with adwords. The problem was they change there rules all the time. It is almost like they know when your beginning to make big money and change the rules to make sure you do not. I was always able to get a good quality score. However, there is always a point when the price of the working keywords go up without any reasion I could figure out. I abandonded the program a while back. Sorry I knows this is not help much.
I personally like promoting CPA offers with media buys only because it's a lot easier to track everything and make quick changes whereas with CB it takes longer b/c you need to message the product owner to setup your tracking link and then if you want to make any changes it can take a few days or more whereas with a CPA network I can change things myself in a back office on the fly.
Media buys can be profitable if done correctly. Always use your own domain to promote products and get media-buys for your domain. Aim for properly priced "followed" links or graphics that will brand your domain, send traffic, and also help your position on the serps. Make sure your domain is hosting updated content that people will come back to read.. Or it's a waste.. You want these people being interested, coming back, signing up for your list, and buying what you direct them to. Stay away from scripted banner rotators, or anywhere that doesn't give you a clean link to your domain. T Most media buys might not pay back on paper immediately - but many are worth it in the long run - if your planning long-term.
It depends on what kind of capital you have as well as time to put into this. I recommend at least $2,000 if you're going to use ad networks like sitescout.com, pulse360.com, etc. If you do direct buys then you can start with less. There's quite a bit to knowing how to do it the right way.
Media buys are tough you need a lot of money for testing and theres a chance you won't turn a profit. I've heard if you're going to go this route CPA is the way to go.