Search engines may run short on paid position ad supply

• Search engines like Yahoo and Google have set off bidding wars among a growing number of marketers who want to place their ads next to search results.
• .According to a report that was set for release on Monday by the Internet research firm Nielsen//NetRatings, the demand for search advertising is growing far more quickly than the supply of available advertising spots.
• ."In the long term, we'll hit a wall where a lot of the search buys that make sense today won't make sense anymore because prices will have risen so high," Cassar said.
• NetRatings reported last week that 48 percent of American households had broadband connections, making it much more likely that users will rely on the Web for quick searches instead of using the Yellow Pages, dictionaries and encyclopedias.
• Over the course of 2002, marketers increased their spending on search advertising by 184 percent, according to the Interactive Advertising Bureau, a trade group.
• Yahoo's Overture unit, which provides search ads to MSN, Yahoo and other search sites, introduced a similar service last month.
• The location-based search advertising market still has far to go, analysts said, as smaller businesses have remained loyal to Yellow Pages companies and the sales representatives who serve them.
• Search engines have long sought to build technology that relies on knowledge given them by users, or observed from a user's history of searches, to improve search results.
• .But advertisers are not interested only in finding cheaper ads on the search engines, according to Pam Stein, manager of Internet marketing for United Airlines.