I think the best answer is: don't! Unless you are a huuuuge company with millions of customers -- end consumers really -- then you are better off doing it your

I think the best answer is: don't! Unless you are a huuuuge company with millions of customers -- end consumers really -- then you are better off doing it yourself or hiring dedicated, in-house staff. The more directly you handle customer's questions and problems, the better equipped you are to enhance your product, your sales materials, you self-help resources, etc. If you outsource it, they have no incentives to help you reduce call volume, which indicates reduced questions and problems (hopefully not reduced interest!). In fact, they have incentive to INCREASE call volume, because they charge you by the unit.