Have way more payment methods to suit people around the world
I have a group with 30-something members, and right now - since the group is small and it's not much work - I still want to pay the fees myself. Since I'm from the Netherlands and creditcards are not so commonly used here (I don't have or want one), I used the Neteller virtual creditcard app until now. Works fine, but they cancelled the app, and to my great shock there isn't a single other payment option other than creditcard on MeetUp.
Now I had to ask my members if I can work something out with one of them who does have creditcard. Well, let's hope. But really, this is not a real solution to a big problem in my opinion.
I work in the online gaming industry and I know that in order to get customers from a certain country, you need to offer their preferred payment option. There are dozens of reliable partners out there, and by adding just a few you can attract a much larger crowd and make your existing members lives easier.
Examples: iDeal, UKash, Click and Buy, Neteller, Skrill/Moneybookers, ClickandBuy, PaySafeCard.