Rolex doesn't care that counterfeit crowns are finding their way onto the secondary market. To them, this problem is of little concern nor consequence; Rolex knows that the crowns they are fitting during service are genuine and from the official source. They'll still charge the end user/owner of the watch being serviced for the cost of the gen crown and simply throw the dud away, which is essentially the same thing they would do if the crown they were replacing was genuine anyways. If anything, this only helps Rolex and the RSC network as it guarantees that the parts they are fitting and supplying during service are correct and authentic; to most owners of Rolex watches, that's what matters and if that's the cost of peace of mind, that's the path said owners will take. This helps strengthen the hold that the RSCs have on aftersales support.