SAN JOSE, California: Online auction giant eBay has begun selling US radio airtime to advertisers. Unsold inventory from 2,300 radio stations in the nation's top 300 media markets is to go under the metaphorical hammer in a move that ratchets-up competition with Google's similar offering [WARC News: 09-Nov-06].

EBay advertisers will be able shop for airtime on the eBay Media Marketplace, originally a forum for cable television ads that began in March.

The new service is being launched in partnership with radio-advertising start-up Bid4Spots. The Encino, California-based firm works a so-called reverse auction: advertisers who join indicate what they are willing to pay for a 15-second or 30-second spot, then radio stations with the available airtime make offers to win their business.

Comments eBay spokesman Hani Durzy: "By combining this radio station base with eBay's reach and scale among potential advertisers, we believe we have the opportunity to create a vibrant new marketplace that will benefit the radio industry and advertisers alike."

Data sourced from Wall Street Journal Online; additional content by WARC staff