Actually, the option has always been there; we just didn't display a "Private" post until recently. I made the change because it allows others to see that there is activity on the ad (they may wish to know in case they are delaying an offer or query). As for email and PM's, we try to DISCOURAGE use of those tools in relation to the market because it takes them out of our audit loop on communications surrounding an item. When someone uses the "Private" checkbox on a market discussion, the seller can see the post in his ad and so can our mods. This makes it easier to follow the transaction if anything should blow up.

Hope that helps!!

Michael