Question regarding paid features using subscriptions

[cmiller1014]

I plan to have a number of things "limited" on my site to encourage the members to signup for paid membership. My question is, what is the best way to make sure this is heavily marketed throughout the site?

For example, if they try to access something that is a paid feature it just gives them a no permission error. Are most editing this template to say something like "You cannot access this until you subscribe" or something along those lines?

Some of my forums wont be readable unless they subscribe, some usergroups will have limited PM's unless they subscribe, etc. I just dont know of an easy way to spell this out for the users without confusing them.

I really wish we could specify "Paid Feature" so that when an error is returned it tells the user they are getting the error becuase they have not subscribed instead of just no permission.

So how are others handling this? Would love the feedback.

Thanks!