". . . customer who ties up a salesworker but never buys anything, or who buys only during big sales. Or one who files for a rebate, then returns the item."
". . . Best Buy was tightening its rebate policies in the case of customers who abuse the privilege . . ."
Apparently a lot of this is driven by a consultant named Larry Selden who wrote Angel Customers and Demon Customers. I think I'm going to go pick up a copy and see how it reads. One thing Selden talks about in the article is a company's willingness to "fire a customer," something Best Buy is unwilling to do.