I don't - I might look at others occasionally for answers to questions if they come up on a google search, but I don't participate. AB is quite enough for me!
Years ago I joined a cat group on e bay. It was quite good but only the regulars posted. Some of us broke away & formed our own personal group. I don't go in it anymore as it gets on my nerves. if someone isn't feeling well, or a pet goes to the vet, they all follow like sheep saying "hope so & so soon feels better", when so & so is better it's "pleased you're or such a pet is better". Then there's the Thankyous for worrying about so & so. Not a lot of any interest is actually said. I go on Facebook sometimes & comment with people I've got to know. Seems daft that some people go on there just to lurk& never post. Not been on here long but am liking it as much more interesting things to read about & comment on.
I'm a member of about ten other forums...clouds, wine making, food, reading and books, travel, medical stuff, etc. I don't spend a lot of time on any of them, or on here, but they're all very useful when I need an answer to a particular question or other opinions about something.