Radio days.

Bid4Spots Inc., an online reverse auction system for last-minute radio airtime, is getting ready to launch a post-auction service called SpotFill--a feature that enables advertisers to supplement their radio airtime auction results by picking up remaining spots in their target markets after the close of the auction.

For stations that didn't sell their entire airtime inventory in the auction, it offers another opportunity to win business and sell last-minute airtime that otherwise would have gone unsold. SpotFill debuts Dec 20.

The company says it created SpotFill in response to requests from large advertising agencies that need to achieve certain rating point goals in specific markets.

"SpotFill gives agencies, franchisers and other multiple-market advertisers a better chance of securing all the prime radio airtime they need to achieve the audience reach they want in all the markets they're targeting," said Dave Newmark, Bid4Spots founder and CEO. "It's our answer to the question, 'What if I'm still short at the end of the auction?' And it's a boon for stations, as well, since they'll have another opportunity to sell airtime."

The auctions take place every Thursday from 8 a.m. to noon. The SpotFill program will run for 15 minutes right after the official close of the auction. During that window, advertisers hurry to select remaining airtime from the broadcasters whose bids didn't win in the auction.

Staff reporter Joel Russell contributed to this column. Staff reporter Anne Riley-Katz can be reached at [e-mail] or at [phone], ext 225.