I've only made about 325 so far since I got my RM in April of 2012.
I give some away but sell most of them at craft sales . Since I started taking Credit Card payments with the Square Card reader on my smart phone my sales have more than tripled . I find them often buying three or four at a time rather than one or saying they will come back with cash like they used to but came back after I had left .
There is tons of information about some of us that have built those sleds and using them on my Woodworking Friends site with lots of threads that are many pages long with pictures and tutorials before we got to the bottom of the ins and outs of using the system.