This weekend i read a post from Custodio, that i have found very useful. The post is in portuguese, so i have decided to adapt the text to english (hope you don’t mind custodio :p)
Well, probably, the majority of you have used adwords, or similar ones, to try and sell something. If this is the case, then you don’t want to drive loads of traffic to your selling page. You want to drive traffic that actually will convert. You must remember, that using campaigns with adwords for example, you will pay per click, and high PPC with low conversion ratios, will sometimes, if not most of the times, ruin your campaign and make you loose money.