So claim one is very very narrow. First it must apply to an item for sale. Second, the discussion must be be started by the computer method and the participant must provide one or more other participants (names/email) to join the discussion. Those other participants must be spammed with the description of the item, the initial discussion and a link that would allow the other participant to buy the item... But there are still other details in claim one which must all be followed to infringe the patent claim. It looks like the other claims are further limitations on claim one, so they are even more narrow.
