You pay for the centralisation and standardisation. Even with google, it's still nice to be able to have one site for one thing, one site for another thing, etc. I could sell stuff on my personal website but I sell it mostly through ebay because that's where all the buyers are and that's how I get the best prices. If I want to find friends from school, I go to friendsreunited.com rather than putting an advert up on my home website because people are more likely to check the 'centralised repository' (if there is one) first. This is the same thing. They're charging for the fact that (in theory) you should be able to get many more people at your group if it's on meetup.com than if it just has its 'own' website. Arguably it's not the case in your group's case because you can self-publicise by having every blogger put a link to the group on their blog. The trick for these things is working out when you've achieved critical mass and are big enough to start being able to charge. Anyway you pay for the fact that you are trying to do something that benefits from there being a central repository of people, data, whatever. They provide that central repository, you pay for the advantage you can extract from that centralisation - which in your case is none.