Remember the Million Dollar Home Page, Alex Tew's brilliant idea for how to make a million bucks by selling ad space for a dollar a pixel, with a 10-pixel-by-10-pixel minimum, on a Web site? (If not, here's one of the many stories that ran about it at the time.) Well, seeing as he succeeded in raising a boatload of money that way, lots of others have since gotten on the pixelated bandwagon.
Pixel prices appear to vary depending on the real estate, but it's all in the highly affordable range. Interesting idea, Jeff.