Thanks all of you, also here I got a lot of valued suggestions.

Our company sell enterprise resource planning software and our webpage is mainly a lead generator.

I will definitely try to find time reading your suggested books, and I may even try to contact some of the gurus.

One of my main concerns now is that we are building a very complex campaign at our vendors account. Next is to make him build this on our account instead. Presume he do not want to let go of our account. He must see the opportunity of delivering also SEO services (this is a SEO company with at least a little reputation).

Would it be normal practice for me asking vendors to build the campaigns on my account instead of theirs, or is there a good reason why they would not?

We are renegotiating the contract next year. If we can not raise all 400k they will raise the fee to 15%. Yeah, sure! When the campaign is built almost to perfect the numbers will definitely go the other way in any case.