I do not thing, that the summer is bad period for selling models.
I will only say this :
Here I have not no sails already 20 days, but in Turbosquid I have the best sales this month there.
Another thing:
We must have statisticks for all the sells and search rezults.I am feeling like a blame here.
And the last : Similar wed statistics for the visitors for May 2015 :
CG Trader : 550 000 monthly visits
Turbosquiid : 2 300 000 monthly visits.
Thats all and have a nice day to all.:)