sue s.

Some groups are okay, have weekly regulars, and no ulterior motives.
On the other hand I am disappointed in those that are clearly for businesses. Well actually they are not clear about that until the first meetup you go to and then tell you about classes they have and how much it cost. Over 300 dollars for the last one I went to. Had I know this I would never have attended. It's basically advertising their classes without really letting you know that until you're already at the meetup. So then it's a disappointment and a big waste of my time.
I do think there are some good honest meetups. I found some meditation groups that are free or they ask for a minimal donation if you care to make one. I paid the suggested fee of a dollar at one, To help them with the cost of the meetup site.
I've also attended a book group and a general meetup for coffee, and a gamers group. There were plenty of others there. And all of the groups have been running a long time.

To some people that are saying it is for losers and the people are weird. Maybe some of them are odd (to you. Whose to say what's odd. Maybe you are), but to say they all are is wrong.
I've met a lot of intelligent likable and fun people. These people are not losers, they are people that want to get together and share their knowledge and interests with like minded people. In this way meetup is a great idea.