AL is the first to solve this. They have quality investors and startups (the 2 critical sides of this network) which is what gets the flywheel turning on these marketplaces.
We see lots of Crowdfunding platforms getting funded and all focus on competing on features and fees but fail to build out credible network participants on both sides and getting liquidity on the platform. AL is doing this well.
Given that Naval also seems smart as heck, this is going to be big and I suspect quite disruptive to the broken VC model.