Seriously - why?
I've been ordering several commissions since around 2010 and I've never really had any problems with it. Well okay, except one time when the artist disappeared for nearly half a year and a buddy and I was stuck with our money gone. Due to some pressure of the Ragnarok Online Euro Community the artist however returned our money and everything was fine again... but besides this one time I always got what I ordered in a timely manner.
Lately this has changed however. In 2013 I had my commissions done in an average of 13 (!!) days, which is wonderful and more that I could have asked for - I usually "expect" a turnaround of ~30 days, but I am fine with almost everything if the artist has a pubic queue or tells their customers what's up.
Still, I am waiting for 5 images ordered in 2013, where the earliest was ordered on September 3rd - that's 290 days ago! And I would even be fine with that, if the artist had his reasons or whatever, but since he (and other's I am waiting for) refuse to answer my mails or notes and ignore or even DELETE my comments on their profiles asking for a status that just plain sucks and I feel betrayed.
I won't go as far as publishing their names, since I still hope that I am an exception to their usual practice and they will get back to me eventually, but currently I am just pissed.
I know that drawing and art in general is pretty much mood based and that art blocks or general reluctance is always a problem, but what is so fckin hard to just tell your paying customers that you need some time and that you will get back to them or whatever.
Currently I am waiting for commissions worth together just above 800€ ... let's hope I'll get those :/