Jambo has launched a test program using radio ads to drive phone leads to select categories of Pay-per-Call Collect advertisers, writes MediaBuyerPlanner. Jambo is buying radio airtime through Bid4Spots, which sells last-minute radio airtime using a reverse auction format.

Jambo will place radio ads for categories of businesses - starting with DIRECTV installers, mortgage lenders, and bankruptcy, personal injury and criminal lawyers - encouraging consumers to call local phone numbers to get in touch with a local merchant. Jambo cycles through relevant matches until the consumer is connected with a local merchant who wants that business - which he indicates by accepting the charges for the call.

Advertisers can choose at that moment whether to accept the charges on a pay-per-call basis. Those charges appear on the merchant's regular phone bill. Advertisers only pay when they receive calls - not for the advertising itself. While Bid4Spots itself is not pay-for-performance, Jambo's use of the system provides advertisers with pay-per-call functionality.