TV ad exchange REVshare has raised $20 million from PE firm The Carlyle Group and H.I.G. Ventures. The company lets advertisers bid on TV ad inventory using a cost-per-action model, meaning they only pay when a viewer responds to an ad. This can be measured based on calls to a specified toll-free number or visits to a website. The model is analogous to cost-per-click advertising online. The Temecula, CA-based company, which claims to have been profitable since its launch in 1989, says that revenue has tripled since 2003, and that it now has 1,500 local broadcast partners. One benefit: advertisers don’t have to pay for ads that get skipped, although it only seems to make sense for ads that implore users to take a specific action, as opposed to branding ads. A possible competitor is the well-capitalized Spot Runner, whose model has been likened to Google (NSDQ: GOOG) AdWords, though it doesn’t use the CPA approach. A spokesperson from the company confirmed to us that this is its first ever outside funding and that it plans to use the money for technological investments. Release.