Why does Cisco bother assigning AM's and SE's to customers if they don't sell direct?

I'm a bit confused as to the relationship a Cisco AM or SE is supposed to have with an Enterprise client. I know they can be very valuable in dealing with TAC, but aside from that, what is their purpose? I mean, you probably are never going to be able to buy directly from Cisco, so what is their interest in dedicating account managers and sales engineers to you? Wouldn't it make more sense to influence things at the VAR level?