Here's our visits report from Google Analytics.
You can see that we normally have around 10,000 visits on a gameday. There's a clear spike on Monday (when pr_capone first posted his thread) up to probably 14,000. I think it's safe to say that we had about a 40% initial bump in traffic due to the banner discussion. The point is driven home even more with this one, which is the percentage of visitors who are NEW:
So as you can see, in a typical day, about one-fourth of visits to the site are from people who haven't been here before (or at least recently). On Monday and Tuesday, that spiked all the way up to around 40% or so. Oddly, there wasn't a huge spike in that regard after the banner actually flew. My guess is just that we've been driving traffic to SaveOurChiefs rather than ChiefsPlanet, so that's where people would have ended up.