Its called reciprocal billing and lecs and clecs deal with it. The providers with the exception of ipkall.com which is run by itltd.net are not lecs or clecs. Many of the numbers are not owned by the sponsors and the sponsors are merely resellers. For example the majority of the les.net numbers are from
Telecommunications - pacwest.com So yes les is paying for it out of his pocket in exchange for advertising his company on the sipbroker.com site. Hopefully they are getting some business off of this site so they will continue to offer many call in numbers.
KieranMullen