Thanks Loco!

Actually after several months' worth of ruminating, this is what I want, and that's
no cloak!

I need a mod for motivating Guests to purchase my audio
seminar before being able to view full contents of the
vB forum that supports the content introduced in the
seminar.

It's a little bit different application than the
mod posted at
https://vborg.vbsupport.ru/showthread.php?t=131985
...since all an unregistered visitor there needs to do to defeat the restricted
viewer access is to refuse the cookie that the mod is based on... then the
forum is once again (in Ted's words) wide open, unfortunately.

My forum is already configured to allow only people who
purchase the seminar to register (i.e. to join the
Registered User group).

What I'd like to have is a mod that for any Guest,
i.e., any member of the Unregistered / Not-logged-in
Usergroup, they are allowed to view the first N characters of any post (N
being adjusted by forum admin) then post content display
is truncated with ellipsis ... plus an admin-definable
message such as: To get the whole story click here
(link = likewise, admin spec'd) to order Jack's introductory seminar.

I'd like to limit Guest viewing in this way to motivate them to
get access to full content (over a decade's worth of work) in my vB Knowledge Base.
HJ