A raft of competitors using the label "pay per call" is about to enter the marketplace and compete for business in this up-and-coming arena. The first of these new would-be competitors for Ingenio making a public push is ZiffTalk.

Another is Thinking Voice.

Call measurement firms, such as MediaTraks and those who offer "push-to-talk" services, such as eStara, are also lining up behind the idea of "pay-per-call," which is widely perceived to be a big opportunity for search and directory companies to capture a revenue premium over clicks, as well as the online advertising business of SMEs.

The market is also global and PPCall will soon be in Europe.

Pay-per-call and its progress in the market to date is on the agenda at TKG's Drilling Down on Local conference, coming up in April. Also, as I promised yesterday, more coming on this subject soon.