Why don't you want to use an exchange? Why should anyone sell their coins to you instead of dumping it fast and easy on one of many exchanges? Are you offering to buy above the exchange prices?
Also, this topic belongs in currency exchange
https://bitcointalk.org/index.php?board=53.0 There are loads of reasons why people would not want to go through regulated exchanges :
1. Tax evasion
2. Money laundering
3. Hiding criminal activities
4. More financial privacy
5. Trust issues after many exchanges were hacked. { Direct transfer without 3rd parties }
6. It might be cheaper {No trading fees}
Well, there are some of the reasons why some people prefer not to use exchanges and opt for "direct" trading as it was supposed to be.
