John Cullum,
We did away with tennis memberships years ago.
Those memberships were started in the 70's when tennis was popular. The initiation and dues were less then golf members, and we found that they came, played tennis and left, without substantive use of the facilities and food service, thus adding very little to the club's bottom line.
In addition, they didn't mix with the golf members, hence we abandoned the program and gave each tennis member the opportunity to join as a full member.
I always say that it's not the chicken salad, pool or tennis courts that attract our good members, it's the golf course, and as such that's where our efforts should be.
Golfers come up in the morning, have breakfast, play golf, have lunch, and either stay for their wives who play in the afternoon, play cards, or go home. At least the utilization patterns help the club and foster comraderie.