I have placed two orders with artscow. I received the first one in about a week. The second one was placed on April 22 two days after the second one and I have yet to receive it. I emailed their customer service and was told that the order was probably lost in the mail. CSR assured me that she/he re-ordered for me.
Email from CSR:

Hi,
I believed it must lost by post office. Anyway, I just reshipped this order to you again and here is the new Order Number:30xxxx for you to reference. I'm surely you will received your order this time. Thank you.
ArtsCow.com

I was happy with the first order especially considering the price. The photos ship from Hong Kong so shipping takes a while. Hope this helps you.