My experience with them :
While looking at 30 something foot express cruisers recently, I would find that they find boats for sale on Craiglist and talk the owners into letting them broker them. Found one on Craigslist for sale and in talking with the owner of the boat, said he had just sent a broker a bunch of photo's and voila ! A few days later, the SAME boat was on POP site FOR $10,000 MORE. Saw others that I had first seen on Craigslist listed on their site also, but those averaged around $5,000-$7,000 more that the Craigslist owner-direct asking price.
If you do look at a boat on their site and you request info, they do a good job at following up with you via email, including emailing you price-drops on the boat you inquired about and when same or similar boats get listed with them.