A short while ago I purged ancient unactivated registrations, sent emails to more recent inactivations (and deleted those that bounced back with invalid emails) and manually activated very recent 'stuck' accounts along with introductory emails, again deleting accounts whose emails bounced back.
Thus we can be sure that our 254 current registrations are valid and pukka.
I've just done a bit more research into our user base and discovered the following:
26 members have never revisited the forum after activating their account
A further 23 members haven't visited the forum since end of 2006
A further 41 members haven't visited the forum since end April 2007
It looks like we have 90 inactive/died/lost/gone away/not interested members leaving just 154 active forum users.
I was looking at the memeberlist the other day and thought with our first aniversary coming up in Sept we ought to start purging accounts with no posts over a year old as no interest .
I'd leave em on - cant think of a reason why, but I would (at least for the time being)
Mind you, i'd love to know how many *active* users there are amongst the 15K "member" of ASSCOCK.
When we were a Kingdom it was run by a King
When we were an Empire it was run by an Empress
Now we're a country we're run by a..........
ASSCOCK have 15k members? They are slipping then, thier banning rate must be dropping! 
Re our dead members - I could send them an email with a bit of a sales pitch (how big the community has become / loads of information blah blah) and invite them to call back and take a look.
I must have joined loads of forums when researching and then promptly forgot about them when the moment had passed, so it might be worth a shot. At least it can be monitored to see whether they do call back.
BTW, it's not chaps with no posts I'm bothered about (nothing wrong with lurking) it's the ones who have never even looked at the forum since they joined that's the issue.
Hapy to go with the flow .