As it stands right now, when a player creates a thread and posts a trade or two in it, and the second trade that was posted is taken, that trade offer is replaced with the words "The attached trade offer does not exist anymore". This is the text that is displayed when someone opens the Message Center. For the most part, that player will see that, assume there is nothing else in that thread, and pass right over it, not knowing that there is an additional trade posted in that thread that they may need. Therefore, I propose that when "The attached trade offer does not exist anymore" is the last post in a thread is displayed, that it be deleted, so that other trades can be seen upon the initial opening of the Message Center.
For example, when a player creates a new thread and posts three trades (A, B, and C, respectively), and when someone else opens the Message Center, they can see the thread title with the text "Attachment: Trade Offer" (C). When trade C is taken, the text "The attached trade offer does not exist anymore" is displayed, concealing the fact that there are two more trades (A and B) still available in that thread. Under my proposal, the post with the text "The attached trade offer does not exist anymore" would be automatically deleted and the displayed text would be of trade B.
Additionally, if trade B is taken first, the text for trade C would still be displayed until it has been taken. After that, the posts for trades C and B would be deleted, leaving the text for trade A displayed. Once trade A has been taken, no further deletions are necessary, as there are no more trade offers in that thread.
In my opinion, this would help players to get more trades fulfilled, because when I post a long list of trades, and someone takes the last one in the list, I have to repost the remaining trades to remind people that there are still other trades to be had. I have been getting around this somewhat by posting trades with a higher number of iterations after ones with lower iterations (i.e. posting one for 2x 10 Copper for 10 Gold after the one for 1x 10 Ebony for 10 Iron). That way if someone takes only one of the Copper for Gold trade's, the trade offer is still displayed under the thread title (I still have to repost when someone takes the remaining Copper for Gold trade, however).