TargetSpot, a US-based digital audio advertising network, has raised $8m from a consortium including one of its customers, broadcaster CBS Radio.
The other consortium members are venture capital firms Union Square Ventures, Bain Capital Ventures and Milestone Venture Partners.
TargetSpot previously raised $8.6m in March 2008 from the same consortium.
TargetSpot advertisers can find consumers by geography, listening preferences and demographics, and benefit from real time reporting and analytics and the company has more than 77 distribution partners, including CBS Radio, AOL Radio, Entercom, Live 365, Yahoo! Music, and MySpace Music.