I think that the fans should save it for the promos that they find annoying. I.e. it should be used to notify Vinny Mac that we don't give a crap about a certain guy.
Like if Chris Masters, for example, cut a promo.. after every line "WHAT?" "WHAT?" "WHAT?"..
I still love Taker's response to the what chants from years ago... say what if you sleep with your sister -- and the whole crowd still did it.