TER General Board
hobby is anything you are into
Anything that interests you
anything you collect.
Anything you spend alot of money on.
It sounds better than "johns " 
IMO, "provider" almost sounds as bad as "whore" or "hooker", since it gives me the same generally negative image as those words do. The term hasn't yet caught on as a full-blown synonym in everyday talk, so its underground meaning isn't universally known (yet). I do chuckle under my breath when I hear talk of things like "insurance providers", though.
The ASP acronym also isn't fully universally known. I don't object to its usage too much, because its meaning isn't well known, and it's handy to use as a "code" for communicating about it with those who do know what it means. I do use it to name both file and e-mail folders on my computer for organizational purposes. However, I wouldn't refer to a specific woman as an ASP. My words of preference are "escort" or "companion".
I have the same feeling about using the word "hobby" as the original poster. I think of a hobby as collecting coins or stamps or baseball cards. Are we collecting pussy here? The term does cover the activity, as it is something of recreation, which the majority of guys who participate are in it for. It depends on each person's personal perspective. I don't consider myself a "hobbyist" because I'm not in it for "recreation" or playing around on the side. For me, it's more of a lifestyle, since it's the only way I'm able to obtain any physical attention from women. I generally don't use the term when discussing the topic with friends or on discussion boards such as TER.