I'm wondering if people see seasonal changes in their click-thru rates? I'd think mortgage clicks would be more popular during spring. Diet clicks higher in january (new year's resolutions).
I don't think you would see a huge shift because your site is going to be topic specific. You may see a few more click throughts, but nothing dramatic to actually notice. That's what I've seen from my site so far. One thing I did notice though, is that I've had a lot more affiliate sales recently.