Ryan,
I seriously doubt it. There are some industry mags that constantly solicit advertising, but since mostly only industry folks read them, I have never bought into the theory of advertising. A small ad in the back of GD would be cost prohibitive and again, not cost effective.
For that money, 99% of the people who look at it are not target customers. I have gotten calls after someone saw an article on me, but have never gotten a response from any ad (I usually take ads out in the local superintendents chapter, for instance, but more to support them)
Most people doing a golf course develop a list of 3-6 gcas' usually getting names either from overall publicity (you gotta get Fazio in here!) or from nearby projects who went through the same process. Some cities broadcast for a bigger list - using NGF or ASGCA lists as their basis for soliciting proposals.
In any case, I doubt an ad does much other than promote general brand awareness, if such can be achieved by a small gca firm.