D'oh! From Brian Caldwell (via Twitter):
What Match does not realize about their "Wink" emails is that they are driving traffic NOT back to match.com but instead the traffic is going to http://www.http.com and I bet their web stats are reflecting a huge drop off in traffic from this acquisition channel as a result.

Moral of the story... always double check your links to make sure you're pointing to the right place. We've all made this rookie mistake at some point, but it can prove to be a very costly one as you scale up your program (especially during the holiday season!).
So, measure twice and cut once...
Always Check Your Links (Measure Twice, Cut Once) - Read More...