OK, I have a Twitter account on a subject which has approaching 35,000 followers. It's literally getting over 500 new followers a day, where the majority are following my account first (it's a popular brand) Anyway... I've currently struck up a temporary deal for January with someone who owns a site dedicated to the subject my Twitter accounts is for - The deal is £35 for January and then we'll have another chat at the beginning of next month. All I'm doing is basically taking his RSS Feed and tweeting when his site has a new post/article and then my followers are ReTweeting and visiting the website. Obviously, I can't be sure how much value my traffic will be to them, but is there a rule of thumb on BHW where you send X visitors for Y amount? It's just to give me a heads up to know, in 3-4 weeks time, if I'm under charging him or not.