Here's an interesting article with Mark Canon, VP of Switchboard discussing Internet Yellow Pages.

Switchboard Electrifies Online Yellow Pages

Switchboard was one of the first Internet Yellow Pages companies, and has recently been acquired by InfoSpace (acquisition pending). As a pure play IYP, Switchboard has spent a significant amount of money sending telephone directories to India to have the information in ads incorporated into their database. To that extent, they probably have deeper data on more businesses than any other IYP.

They also offer a private label solution for companies such as AOL, Knight-Ridder and TransWestern Publishing.

The acquisition gives InfoSpace a platform in which to serve local ads from multiple sources. Currently, all InfoSpace IYP traffic is diverted to Verizon's SuperPages. I understand that the agreement between InfoSpace and Verizon ends later this year.

I suspect that you'll eventually see InfoSpace driving their IYP traffic into the Switchboard platform, but incorporating Verizon's higher paying advertisers into the system.

I do question the validity of the traffic numbers being quoted. It simply seems far too high given the two players involved. Perhaps they are including some of the less monetizable searches such as maps and white pages in the overall numbers. They are significant, but I wouldn't classify them as important as Yellow Pages searches.