Location specific is better, because if you just know that a particular spot has the kind of people and atmosphere that is inviting and pleasant to be in, you just go there. No need to check-in or schedule a meeting or anything else. Frequent regular interval fixed-time events are good too. I used to part of a racquet club that just had an open session all evening twice a week. You just show up and play and so did everyone else. You put your name up and are just play whoever is next for a game, then wait, then play someone else. You get to play a variety of people and when waiting your turn you can chat and get to know the other players. 5 stars system.