(Hey look at that, two shiny pennies!)

I don't think a vendor should publicly disclose that someone bought from them. Say someone like CC, who is a respected member of several boards (not that I respect you, you old fart!) makes a purchase from an online vendor. Then that vendor makes a post saying something like "You can trust me, CoventryCat86 does!." In essence, that vendor is using the members name to advertise their business. It may not be worded that bluntly, but it's the same thing. I'm guessing that the member in question receives NO compensation, therefore it should not be done.