Does this happen to anyone else?

[Toby]

Originally Posted by Webby

...you elect to use a sponsor and throw a lot of traffic at them and the results can be excellent for.. usually around 8-12 weeks - then conversions sink into oblivion, tho traffic levels and sources of the traffic have remained the same...

Part of this can be explained by the "newness" factor. Even if the sponsor isn't new, their content is most likely new to at least some of your current traffic. You'll get an initial spike in sales that will taper off over the first few months after you've used up most of the "fresh" promo material. Sometimes that taper is to almost zero.