Are the promotion method white hat??

So I got a little question... Are mediabuys whitehat??? I mean to go let's say adbrite and buy ad space on some site to promote your campains... is that white-gray-black hat?? I think that it is whitehat... So could someone pls explain this to me... would appreciate it...

I know it's not nice to point peoples on external sites but maybe here will be nice to make an exception ... try and read this article

Its completely whitehat. Good traffic. I'm thinking about skipping ppc and going straight for it. Can anyone recommend as far as media buys:
Do you wanna go through a network? if so what are some good ones?
Or do you wanna go through a indie site?