How many of Call Centres in India have been successful at Outbound/Inbound Campaigns!

That is the calls made/received have been successfully converted into revenue without being disqualifed as not a sale for various reasons that could be assigned by the outsourcing agent/Company.

What are the pre-cautions that have been taken while entering into a contact with such outsourcing agents/Companies, as we do not know wheather such a company exist and where are they located in USA for example etc.

What is the extent of transperancy involved in the whole deal so that there is no loss to the Call Centre, the Outsourcing Company and the targeted client.

May I request all the experienced persons to share their view on the above matter for the mutual benefit of all in the Call Centre Industry.