Just checked out http://cgtextures.com/ (nice link BTW) and an ad for Seamless Texture Generator came up on the second page I visited.
As you no doubt know, wild fluctuation are common in statistical systems with a small sample size, so it's not surprising that you get those sort of results. There may also be seasonal factors which can affect results in various ways (holiday periods, etc).
EDIT:
As GW mentioned below, it's interesting hearing about your experiences in selling your product, particularly in regards to pay-per-action advertising. I have a world editor nearing completion and am starting to think about my options for selling it.
As you no doubt know, wild fluctuation are common in statistical systems with a small sample size, so it's not surprising that you get those sort of results. There may also be seasonal factors which can affect results in various ways (holiday periods, etc).
EDIT:
As GW mentioned below, it's interesting hearing about your experiences in selling your product, particularly in regards to pay-per-action advertising. I have a world editor nearing completion and am starting to think about my options for selling it.