The (internet!) "banner" in question is actually composed of four discrete ads, presumably from four (well, three, as one ad is repeated) different sources.
"Project Wonderful" is a company that buys and sells ad space on blogs and elsewhere, with the cost of such space being very transparent and the space going to the highest bidder. It is a *very* useful service for someone paying for ads, as you can see exactly what return you are getting for your money and you can pull a non-performing ad immediately (to the second). I've written about it on ESMB. I last placed ads using PW only a few months ago.
The cost of each of those little ads in $0.03 (or less) per day.