Mobile Pay Per Call Advertising

I’ve become interested in mobile pay per call advertising, based on a couple of simple high level observations:
- Many types of businesses are naturally phone-based in their new business generation process. Think pizza shops, plumbers, lawyers, and pretty much any other type of business that would naturally advertise in the Yellow Pages.
- Historically, online pay per call has been has been hamstrung by the need for the end user to switch from the PC to the phone (by dialing a number on their PC screen, or entering their number on their PC and getting called back). It seems like this PC-phone context switching would lose a majority of the potentially interested callers. But on a mobile device, the user is just a simple click or finger touch away from making a phone call. It seems like this would have a dramatic positive impact on Call Per Impression ratios.
Google has recently relaunched their click-to-call capabilities (Google’s Jan 2010 Announcement) on high-end smartphones. ReachLocal sits in a strong position to use its direct sales force to interface between Google (and other publishers) and the many disparate enterprises interested in generating inbound phone calls. Perhaps a transition from Online Pay Per Call to Mobile Pay Per Call is modest enough that the existing online players will dominate in the adjacent mobile space, but I can’t help but wonder if there is a mobile-specific approach that is more effective than what has been tried by the online players to-date.