3k uniques? 1st page or 2nd page? Has the sponsor changed up the tour(s)? Added more traffic from varied sources (eg TGP links can be a bit on the 'blind' side so you get higher ctr but a falling ratio)?
In all honesty 3k is a little bit too low to start panicking *just* yet, 2 quick sales and you are at 1:1000 which depending on your traffic source yes, is still a bit high. Take another look after 10k unique 1st page hits and if they've stopped converting for you just move on. Happens to all of us now & then
