The strike system works much better because most sellers will have their settings set so these serial offenders can't bid on or buy their items. Some of them can spend quite a while wondering why suddenly they have restrictions on who they can buy from. Sure, they can open another account to get around the blocks, but ebay frowns on that and they can get into even bigger strife. If someone doesn't pay, as already mentioned, open a case, close it 4 days later and add that buyer to your blocked list. Plus, make sure your settings are set so if they do have 2 or more strikes, they can't buy from you in any capacity.