http://motherboard.vice.com/read/how-silk-road-bounced-back-from-its-multimillion-dollar-hack
Even though they try to hide it, due to this article we do get an idea of the size of the site. Combining the following information.
In total, an estimated $2.7 million worth of bitcoin belonging to users and staff of the site was stolen.
and
the administration of the site has not made any commissions on sales. Instead, every time a purchase is made, a five percent slice of the cost goes directly into the account of a randomly determined hack victim.
and
The administrator of the site expects to have everyone repaid by mid-June, assuming that the site's current usage levels remain stable.
A five percent slice means that $54 million in transactions has to be done to repay everyone. That means that SR2 will have transacted that amount between the time the repayments started and mid-June.
That's a pretty large amount, especially considering a lot of user fled after the hack. So before it must have been a lot bigger.
It'd be interesting to see a comparison of Agora's monthly revenue to SR 2.0's. I honestly don't know which one is making more money at this point.