Yes. Organizers pay a fee.

Yes, if you are an Organizer, you are charged a renewable fee to start a group and keep it going. Meetup Organizer fees (which vary by the # of members) can be deducted from your credit card when due.

If you are joining an existing group, the group organizer will decide if there is to be a membership fee or not but most Meetups are free. If the fee is substantial, I would ask what it is used for. Depending on the group, they might have to rent space and buy insurance.

If you want to start a group I'm not sure if you'll be charged for the service, but if you want to join a group then most groups are free. All of the groups I looked into and the few I decided to join are free. Though, mind you, there are some that say they need to pay to start a group and therefore will charge a small fee [$5 -- $10, though that really adds up over time!] for your to join their events. I hope that helps!