I have always believed that voice communication coming after reading some information about a seller (B2B or B2C) aids in the "conversation interaction" that brings buyers and sellers together. So, when I first heard of "Pay Per (phone) Call", I liked the basic premise, and I still do. But, for many B2B seller-advertisers like Tower Tech who makes Cooling Towers for industrial purposes, I believe, that most buyers and specifiers (engineers) want more written information upfront than what can be put in Pay Per Call ads.
This August, 2005 BtoBonline.com article caught my attention as it mentions Tower Tech as being invited to test the launch of Verizon Superpages's new version of this. Tower Tech seemed happy with the growing results in early August, but it looks like they only have their listing and a nice Sponsored Link ad, as of today? My opinion is that most of their buyers want to see their web site first before they call Tower Tech. Most industrial buyers want to be sure that the supplier has exactly what they want, or has the potential to make it, before they get on the phone with a salesperson.