Sycraft
Probably because subscription is what we've always called things like this at work. We have a fair bit of software that works like this where you pay $X to get the software, and with that comes a perpetual license but then for $Y/year you get to have updates to the latest version. Vendors often call it a "maintenance subscription".
So that's just the term I'm used to. To me subscription implies a periodic payment (normally yearly for software). The terms of the subscription are what differs. Like with Symantec GSS it is a subscription like Sonar has, if we cancel we don't get updates but keep the license, with Mathworks Matlab it is a subscription that must be renewed to have a license.
Well the answer is this isn't Symantec. CW as the developer has named it a membership. Its the term preferred by CW and we users have adopted it as well. One big reason is some people don't like the idea of a subscription where one loses the right to use the software if one is not current with a payment. Plus because we have a very strong forum the idea of membership is a better description of the nature of what goes on here. We work together to help one another with any issue a member encounters.
The semantics aside we have a community that is alive and well it fellows that someone purchasing Sonar automatically becomes a member even if they never come here. There is no requirement to purchase Sonar to be apart of the forum but I believe if one is interested in DAWs and went to the trouble of logging in they too are members. Members of the forum.
I rather be looked upon as a member rather then a subscriber. It implies a closer association to other like minded people. We share what we know with each other to a degree that is rather fantastic. Give us a problem to solve and watch the fur fly as we seek an answer.
When we think of this in the above way I think it helps to fundamentally change our relationship with one another in a very positive way. We no longer need be off on our own by ourselves trying to get answers. We can call upon the collective knowledge and wisdom of the members.
In a virtual world of a forum it helps to humanize it by calling it a membership. It can be anything we want it to be. Thus I support what CW has started and asks us to refer to it with the term of membership.