For a big site it might run even but for smaller sites there's no way. I'm thinking running costs are pritty high and I don't think 60-75c/day make much of a dent in that bill, sure you get more publicity with having your own ads out there but at what cost? I rather keep the site clean then or offer free advertisement to other Amiga sites in return for the same favour... that way one can also design the adds to fit in with the design much better and avoid aysoering misscolored adds.