I agree, although some people like to make contact with different companies and entities to widen their supplier and business contact range

But then surely that is the point of having several services under one roof....to keep them from looking elsewhere? If i had a seperate site for my traffic business im preety sure i wouldnt have sold the amount of traffic i already have.

when you could efficiently focus your energy on one true service?

Well.....whether it is in the same site or seperate you will have to split up your time for each service. I personally think if the product is good enough it will sell. I rarely promote the traffic i sell and because people are satisfied with the level of service i give them (when buying banners) they assume it will be the same with any product i bring out.....which of course is true.