Recently, Larry bought a prepaid calling card. The rate was 1.8 cents per minute, or just about 0.8 cents per minute for domestic long-distance profits left to the service provider and distributor of the cards. That\u2019s not much profit - so we wondered about the competitive voice-over-IP long-distance market, asking ourselves if VoIP providers can survive on such low margins.We asked Sarah Hofstetter, senior vice president for communications at Net2Phone about it, and she confirmed that domestic markets are extremely competitive for long-distance - that VoIP providers are fighting over a few tenths of a cent per minute.The good news is that growth opportunities are still available outside North America. In the case of emerging markets like India, Asia, and Africa, Internet cafes are turning into VoIP phone banks. VoIP is making phone calls affordable and available where calling was neither before.For the enterprise, quality-of-service advances in codecs, gateways and network-planning tools have made VoIP fully \u201cready for prime time.\u201dAs for the SIP vs. H.323 vs. MGCP debate, there isn\u2019t one for Net2Phone; the company supports all three, and offers network interworking between the protocols. Net2Phone has also found success with cable operators that want to enter the \u201cphone\u201d business. Given the market\u2019s acceptance of cable as a preferred broadband technology, that\u2019s a boon for those who want a broadband alternative to DSL and can\u2019t get cost-effective fiber connections.Looks like VoIP service providers are going to be around for a while longer - and that\u2019s good news for both consumers and enterprises.