Indeed a curious comment from someone who's been a member for 18 months and has yet to record a score. :)
With so many other video golf options out there, both free and pay-to-play, I think charging a members fee would be suicide. Look at the pay tournament participation. Cumulatively, the Amateur and Hack tiers average about 20-30 entries per tournament. Most of those players, such as myself, play all of the tournaments. 30 people is hardly a drop in the bucket when compared to the total membership of the WGT.
Sure, I'd be willing to throw down a few dollars in donations here and there but, a monthly fee? No, you can't do that. This game isn't up to the level of WoW or any of those other $10/mo games out there and won't be for a while. In this economy, I'd think the average person (the WGT target audience, not gamers like the WoW fanbase) would have a hard time justifying the monthly expense for a luxury such as this.
Micro-transactions are definitely the future here because it allows people to spend money when they can and still leaves the door open for user donations. Overall I think that system would outperform a subscription based service. I think you'd be hard-pressed to find someone who will donate AND pay a monthly fee.
Anyone else care to weigh in?