@Peter
I agree that getting sales calls is part and parcel of running any business, but we don't want our members to feel that joining mtvan makes their phone ring off the hook with people trying to sell them fuel cards and expensive memberships to rival sites etc, so we're trying to put a few obstacles in the way.
We have been working on the "reputation" idea for a while. It is still likely to be tuned and developed in the light of experience.
We actually devised it as a way of encouraging and rewarding participation, not as a way of stopping spammers, but it serves that purpose equally well.
The problem we were really trying to solve is where some couriers, or even wannabe couriers, join and don't really get involved. No photo, no description, no ID, no forum posts, just an anonymous-looking entry. This is pretty useless to Vendors looking for a courier, and therefore pretty useless to the anonymous courier.
We're now beginning to say that to get the most out of mtvan, to see and be seen, you need to invest a little time and effort, to get 200 rep. So it's likely that soon the directory will optionally filter out those lower than that, for example, so Vendors can search only people actively participating on mtvan.
As things stand now, a new courier company can still contact you if he has less than 200 rep, though only through the site. Although it's not as instant as by phone, it's still a means of contact.