I sometimes browse them & view the forum to see if it's one I would like to join. I think it's a good way to help promote & help each other out. I've found some interesting forums I wouldn't have saw otherwise.
So, do you look at them? If so, how many do you think you have joined as a result?
If I see that a site or a forum has affiliates I will take a look over them and see if there are any I would be interested in. I have on odd occasions found sites that I have been interested in and become an active member of them. I think this is why I like affiliates as it's another great way to not only find new communities but also maybe have yours found as well.
If the affiliate link is shared by someone who creates interesting posts, I will surely check those links and even join the platform if I find them interesting and useful.
I tried doing an affiliate exchange thread on another similar site to this one, but no such luck or success with it. I do tend to look at them before reaching out or approving of the forum/site, yes.