I was recently approached by a developer/CCO of a fairly popular app (100,000+ downloads) about promoting his app on my Twitter account. My account has around 30,000 followers and receives anywhere from 200-600 retweets per tweet. I have previously charged people $5 per tweet, back when I was in the 15,000-20,000 range although I've almost doubled my followers now. The other thing is that since this is a legit company, I feel like I could charge much more than if it were an individual... Is this true? Could anyone give me an idea on an appropriate price to throw in the air for him to ponder with? Thanks.