I think Dominique and the Professor really sum it up and there isnt much to add – quality of traffic and good landing pages is what its all about.
I just want to pick up on a point made by Dominique, specifically that there are “autodownloads” which skew the stats. this could be through your specific sources of traffic.
Check your referral logs and see where the traffic is coming from; you could be buying bad traffic.
I also have made a ton from the grilled cheese guys but only because I have built up a long term player base and every now and again a whale comes and skews the stats up. The longer you fish…