Yahoo! Inc.'s (NASDAQ:YHOO) decided to shell out $680 million to buy the 80% of online advertising auction company, Right Media, that it does not already own. There is a temptation to view this a a counter to Google Inc.'s (NASDAQ:GOOG) purchase of ad serving company DoubleClick, but the deals are hardly comparable.

Google bought the better business. The ad-serving industry, in which DoubleClick is the largest player, touches almost every significant site on the internet. DoubleClick has its own ad exchange business that will compete with Right Media.

Right Media is in an unattractive niche. It acts an an auction market for online advertising inventory. But, the largest websites are unlike to sell at auction what they can market directly. This would, in most cases, leave firms like Right Media with fairly unattractive inventory. User-generated content created many of these advertising impressions, but it is still unclear what value MySpace pages have to advertising.

Yahoo! has to make some bets to improve its position against Google, AOL, and MSN, but the ad auction marketplace does not seem to be a good place to start.

Douglas A. McIntyre is a partner at 24/7 Wall St.