We all looking for the best so, I am asking everyone that expert in this matter, and might help me and all readers, I am making a research for the best Phone Verification Service to be used and integrated with websites. Which also can be used in SMS verification service also for Mobile Phones. So, I am asking everyone that has existing business to review current service that he is using, or recommend it for me and other readers.
maxmind.com. Its cheap, and works well. I use it since my digital goods can be easily carded without some kind of protection. If you use a shopping cart like oscommerce, then it integrates easily since there is a module for it already. The customer must get called back before he can proceed with the purchase. If you have a different shopping cart, you may need to integrate it yourself.
Currently i'm using phoneconfirm.com coz their price is within my budget and the verification process can be tailor make to fit into my company requirement.