Forum Usergroups based on post counting
 

Hi, On my forum I actually have about 1360 registered members.

On my previous fourm based on smf I use to give some more features to the users by change several permission based on group.
The group was based on the post counting; for example:

user with 0 post can see only the presentation board and rules , no pm or email no anyone, no reply others post.

Users with 1 post and over can do almost everything except to contact via pm other members.
Users with 50 post and more can have access to PM

So, actually after my import all the users are "registered users" so now i start to create promotion to subdivide the groups.

I start to promote the "registered users" to "observator group" that should be part only users with 0 post.

I setup the promotion like this:

User group : "registered users"
messages : 0
strategy of promotion: messages
Kind of promotion "does not matter" (i don't understand the differences)
method of comparizon : less than
move to usergroup: observator

is that correct? because it does not work,
can u please tell me also how to restore the group assignment just in case of error?
thanks