An artist my partner and I have commissioned in the past was taking emergency commissions to be completed the following couple of months (early in 2013). We were the last of twelve to sign up in that batch and there were two or three remaining from the artist's previous commission list so a wait was expected and accounted for. The time period in which the emergency commissions were to be completed passed, with only two of the older commissions completed and none of the ones from the emergency batch. Since then the artist has been slowly but steadily completing commissions on the list without public updates as to status.
Normally I would have sent four to six status requests at this point (as I spread them out to once a month or once every six weeks if there is signs of activity from an artist) but the length of the artist's public To Do list has stymied me from making contact. Having seen other artists skip over clients who have waited longer periods of time for their artwork in order to cater to more vocal customers I find myself wary of making much of a fuss.
Do other people take into accounting an artist's To Do list when weighing whether to request updates or WIPS of their work?
(Note: I have no intention of posting a beware on the artist in my example or entertaining speculation about them, this is simply for my own edification and potential community discussion.)