Google is testing click-to-call (pay-per-call) ads on search engine results pages, reports ClickZ. Users who click on phone icons appearing next to sponsored search listings can enter their phone number; the system first calls the search user then connects with the merchant. Blogger and tech consultant Greg Yardley, among the first to notice the new feature, provides a series of screen shots of the process, which Google describes in an FAQ item.

Google also takes note of privacy concerns, saying in another FAQ item that it "won't share your telephone number with anyone, including the advertiser…. In addition, we'll delete the number from our servers after a short period of time."

Google has only confirmed that it is conducting tests of a pay-per-call model but would not provide any more information.