There was a long article in the Wall Street Journal a while back about people who take advantage of liberal return policies and price reductions. Outcome of the story was that many retailers began telling those customers they were no longer welcome in the stores. Some of the examples they discussed also included women who would purchase expensive clothing to wear to a party, then return it for a refund the next day.

I too sometimes play the games allowed by the systems, but recognize that they may eventually result in either a change in policy for all customers or my being banned from the store or enterprise. This happened with S&L's in the 70's that paid interest on your deposits from the first of the month deposited but had no penalty for frequent withdrawals. You would open accounts at two institutions and bounce deposits back and forth between them, essentially getting twice the interest... and rates were 7-8% in that period. There was even a book written on the process, "Don't Bank on It". I was able to do it for three months; then they closed my account and sent me a check.