Some of their agents actually are out on social media, mostly LinkedIn, looking for this type of business. And no, they're not the only ones.
There is still an element of it going on at CHR (but small I would say), and when MSM was seperate from Wheels there was a rep who would continually call on me to ask to help with our freight.
A lot of Canadian brokers actually used the strategy of becoming a US broker's 'go-to' when the industry was in its infancy. There may have been a place for it at one point but that time has passed a long time ago. With information being as free as it is today, there is no reason to broker through multiple hands anymore. There is no value in it ... only risk.