Ars Technical has an article that reviews several signals that suggest the boomtown days of online advertising are about to come to an end. The sharp drop in the sales of high end electronics is bringing a related drop in advertising for those devices, but the article suggests the bigger driver in online ads is a maturing of the marketplace, where businesses are finally figuring out just what an online ad is worth with respect to click throughs and sales. Businesses that are not getting results with their online advertising are cutting back, and that drives prices down. The article makes a particularly interesting point about the difference in value between a TV show or a movie and a Web page--the Web page has significantly less value because it occupies the viewers attention for a much shorter period of time and also has many outbound links. A TV show or movie, by contract, has the viewer's attention for a more predictable (and usually longer) period of time. That makes TV and movie ads more valuable.