Didn't know Coingig was closing....
From the homepage ...
"Coingig is going to be shutting down, we will allow 2 weeks to process all orders so we can make sure everyone is paid."
I don't know why Bitmit closed or Coingig is heading the same way? I would imagine them to be doing fairly good business even taking just a couple of % of total sales. Bitmit had a lot of volume going through when it was open, Coingig less so but is / was a really nicely laid out site. Maybe due to factors we don't know about like banking issues etc.
Bitdazzle is very nice looking but lacks really basic marketplace features like order management tools and a feedback system etc. They are working on it though.