Shaddows - 4:43 pm on Nov 2, 2012 (gmt 0)
No, we get a temporary shift, then normal traffic (plus zombies- note this is extra traffic, not replacement traffic) then a completely new referral pattern. Previously unloved (but no less worthy) pages get traffic and increased sales, while solid sellers suddenly stop selling completely.
On one scary occasion, a number of our top selling lines dropped 10-15%, but close analysis showed revenue was mostly made up elsewhere. Over time, sales on the top lines returned, but we also kept the new revenue as well. As I said, it can be disruptive but has usually worked out well in the end.