[Tryk]

I don't know that this blog contributes to the solution, with a TL:DR:

"[...] Identifying which side of the marketplace is more scarce and focusing on supplying that."

[gomox]

You mean, other than describing 5 possible approaches to the "bootstrapping a marketplace" problem, including a specific solution that worked in the real world to get to 7 figures GMV for the exact marketplace the OP is describing?

:D