I know of 2 of my affiliates who's traffic fluctuates like yourself. One week they convert around 1:200 and get 25+ signups, then the next they're sending the same hits and converting around 1:1500 with obviously less signups. Often they msg me and we discuss the stats and possible causes but when nothing has changed it just doesn't seem to line up. I just assume it is a saturation thing in these cases.
