I found trading in four or five middle grade pipes at SP gave me a discount on one new pipe I really wanted, which for me beat the time and labor of peddling the pipe online. It was less than I expected, but counting the need for them to clean and sanitize the pipes and sell them, it was probably fair deal. I'd do it again. If I had a pipe that represented a larger investment, I might work with someone to sell it on commission; I think I'd want a bigger cut of the deal. But compared to trashing pipes or giving them away (unless you really want to gift someone) it's not a bad plan. From this experience, I'd guess they sell mostly the pricier pipes online, with pictures and write-ups, with a few lower cost pipes sprinkled in for variety. But most of the lower cost pipes taken in for store credit, I believe they sell as basket pipes in the store, or otherwise re-sell them off line.