I have belonged to a couple of clubs over the years. The one I belong to now is a "meetup" group. We have an organized ride somewhere every day. Sometimes two rides. Morning and evening. I can always find someone to ride with. We do have bike shop discounts and some other discounts. We have rides for all levels and have a no drop policy on most rides. We have around 1000 members signed up although there is a much smaller "core" that attends rides. I seldom have to ride alone if I don't want to although I can if that is what I want to do. We are centered in the Chino area of Southern California. The name of the club is "BoBies" (butts on bikes). Great group and great organizers. Keith and Janet Berg started the club and are the overseers and keep things going. We get new members all the time. Very friendly folks. No snobs in the group.
I joined because it has become a focus of my cycling and gets me out the door. I really like the social interaction as well.