There's not much info on it out there freely. The guys making money doing it only share with their buddies while drunk at affiliate conferences. Until now...
I think that 'zerofriction' does it well with media buying myself and also the Mexican couple describe it in great detail. One good way is to simply find a site with good traffic in your niche of course and offer them some $'s to put your banner on their site. Preferably down one side of it and make it a big long one for maximum exposure.
Media buying normally goes by the 1000 impressions, say text ads or banners. You buy several thousand and show your banner to places like myspace, facebook, blogs and forums. Someone clicks on it and they might sign up with just a zip code remit or a sale. Maybe only .90c to $40. Sometimes it's better to keep getting .90c signups. Then like affiliate marketing in general you get paid and can track your sales through you tid ID thingie on your network. It said to be more profitable than normal affiliate marketing; but your competing against some big players.
There are a number of media buying sites. Best thing to do with media buys is to target your demographics! To do that, just do some simple research on Alexa and quantcast. After that, its all about the quality of traffic. Cheers.
you should check out Traffic University the owners of the website Carlos and lupe garcia get like a million plus visitor a MONTH with media buys. Yes a million targeted visitors a MONTH!!!
That's pretty decent traffic. Yeah, it all depends on what you have to start with both knowledge wise and cash. I started with $2,000 using an ad network and still do it today. I love media buys due to how targeted you can get. There are ways to reverse engineer the whole process so you know what's already working for others...their landing page, where they're buying their traffic from/which site(s) they're placing their banner on, which offer they're promoting and what ads they're using...very good method to use to help you minimize your risk.