said by tbeckner:I know that they buy numbers from small wireless companies
Vonage does not "buy numbers from small wireless companies"; they get them from a small number of CLECs (from what I've seen, Focal/Broadwing in particular.) Number pooling (where carriers receive numbers in blocks of 1,000 rathern than 10,000) can make numbers look like they are assigned from wireless carriers, if you look at only the NPA-NXX and not the NPA-NXX-X.
(NPA-NXX-X assignments are at »
www.nationalpooling.com/ ··· teTyp=FR If a NPA-NXX-X is not listed there, the number belongs to the carrier who has the "whole" NPA-NXX unless it was ported out.)
One reason VoIP carriers in general have issues with keeping phone numbers in stock (I've seen the same happen with VoicePulse and others, but not to the degree I've seen with Vonage) is that NANPA, which assigns phone numbers, is tightly managing number resources, and the CLECs VoIP providers use can't let VoIP providers or anyone else have "too many" numbers just sitting in reserve for future customers without raising the ire of NANPA. (Most VoIP providers order numbers in advance of customers actually signing up for service rather than dynamically requesting numbers from CLECs when a new customer signs up. There are a number of factors for why that is.)
A related problem I've seen with Vonage is that they still have no coverage in smaller markets (like Chattanooga and Knoxville, TN) where P8, VoicePulse, CV, and many, many others have numbers, mostly because of what appears to be reluctance to use more CLECs than the few they do now. Sticking with only the largest cities isn't a good way to grow a telephony business...too many CLECs competing in the same small number of cities for the same customers is one of the reasons the "CLEC bust" happened.
-SC