"enterprises"? of what sort? a particular industry? Networking with people in that industry at their events, perhaps even speaking at those events, would do you a world of good, ime.

Find some local networking groups that deal with the industr(y|ies) you target, and start to infiltrate their ranks :)

P.S. "low/no cost marketing" is one of the sessions at http://indieconf.com this year :)