Have you ever had a chat with a bot?
Just browsed Google for bots as they take a person's pictures off. Seems we now have a new Bot Brunch opened up. A person can order ♡ Sex On The Beach & Woo Woo and Pornstar Martini, which shows how out of touch I am with what is going on local.
I would think that any specialized forum (i.e. for seniors) would have tons of guests visiting that mostly decide to read and not actually sign up, at least right away.
Guests can read lots of the forum to get a feel for whether they might want to join. Obviously a guest can't post anything, nor see any media that you have marked for 'members only'. Bots help to get the site listed on the search engines. We used to call bots 'spiders' or (web)crawlers. Fascinating to see how busy they are though