I participate in swaps on one group only. It is one I help run. We are a small group of just 61 members currently, not all are real active. IF someone does not complete their swap...only one chance, they are kicked out. ( unless they let us know ahead and are really ill etc...) with a small group we know our members. We also have members that are "swap angels" and send to the receiver if a swapper didn't send.