ABM = always be marketing. If you have a low-cost way to get yourself in front of a large # of clients, it's worth doing (whatever that may be).
I've never understood the kumbaya, big warm hug theory on lawnsite of "oh I know the guy who services those 200 accounts, those are off limits." Unless you guys are so tight you're attending his daughter's baptism and he's having you over to shoot pool, I don't get it. It's business. If I lose business to someone I know, I assume that either they were a better fit for the client or they sold themselves better, and I need to improve some part of my game. I'll still sit with them at next year's Techo showcase or whatever.