There are costs to run this site - non-debatable. Reasonable for Robin to find some way to recoup those costs and make some money for his time - to me non-debatable. Few challenges with current approach to recoup:
Donations - It's voluntary & not everyone is making donations (as seen by the heart). Of those that are donating, is it enough to cover costs? Like the tootsie pop commercial, we may never know. 34K members no clue how many donate, how often, what value. Challenge is if you do donate and then now on top get charged for pinside successful sales you feel like you just payed twice. Then there's the emotional aspect.
A donation or buying Robin a pinball machine (one time awhile ago) to say thank you are community giving based contributions. You give based on emotion, appreciation, and positive feeling of being part of something you believe in - supporting a community. When a fee is now asked for successful sales in market place plus local threads are being moderated more heavily to enforce listing policies, now it's a business - emotionally viewed by members. The foundation feeling of "community" is challenged a bit (don't want to over exaggerate either). Is it "us" or is it us and them (business).
What other ways to recoup costs to maintain the house that Robin built? Charge for advertising (including hosting sponsored threads/microsites for Stern/JJP/others) or charge an annual membership. I get charging for advertising is something frowned upon, but its a way to generate revenue without taxing the community. Sort of an accepted and sometimes irritating standard. And back to membership. A little something to say to support this community we need a little annual fee to keep the lights on. Once inside, enjoy. Buy, sell, trade, make mods, share tips - this is your house. Emotionally it still feels like a community - logically we need to help keep the lights on.
While successful market place optional sales fee sounds like a good idea it's in contrast to keeping heart donations. Why? Aggressively moderating doesn't support "optional" donation. Emotional then logical reactions.
I promised I would stop but saw the thread open up again on this topic. Just sharing why reactions are mixed. In the end, a fee for selling through marketplace is being asked - local threads more aggressively watched - it is what it is I guess. Change is inevitable.