As you said, "They'll only be viable if a whole load of people do it." Although that particular site has managed to survive for 20 years largely because a load of stamp and postcard sellers decamped to it years ago when ebay tried to impose some restrictions on their postage options in the past.
In some ways it's a better site for selling the sort of slower selling Collectables that ebay now seems determined to get rid of. I've said it often enough on here that people buy my glass there because they can find it . No bias in the search towards Sponsored listings or quick selling 'new in a box' goods. The only reason things sell slower is because so few people know about it and use it regularly.
If it establishes a more widespread reputation for being a place to find those rare, obscure and quirky collectables that ebay was once famous for, it could easily become something like the 'old' ebay, before it became so fixated with businesses selling mass produced new stuff. It certainly isn't full of businesses demanding restrictions on private sellers and how many items they can list or how they sell them.
It might be a bit primitive by today's standards, but is that necessarily a drawback? Private sellers don't really need all the analytics and statistics that businesses do, but which we all have to pay for one way or the other. Nor do they have provide shareholders with endless returns that require regular fee increases which, at the end of the day, is what the BPF, Payment Holds and 'Simple' Delivery are really all about.
If enough 'little people' took the leap of faith it might just possibly become a sanctuary for person to person buying and selling, free from the pressures of greed driven US corporations. Like ebay started-out as.
