Would it not be an idea to delete absent forum members, We have 2673 registered members, but over 1800 have not been on in the last year.
Maybe, but some come back, we've had several return after longer than a year. My brother for example was one of them.
We also have a lot of spammers in that number that we'd rather keep banned as it builds our list of banned IPs, email addresses etc which more importantly helps our cross-checking when we review new members to see if we should ban them. It's not as easy to reference if the member is deleted.
My 2 cents is that it does no harm, so leave them. Not sure what others think.