Marketplaces are incredibly difficult to pull off successfully. What I recommend is to find a way to add value to one side of the equation (most likely for the

Marketplaces are incredibly difficult to pull off successfully. What I recommend is to find a way to add value to one side of the equation (most likely for the sellers), and build up a sufficiently compelling argument for them that you can become profitable simply as a SaaS business for them. And then, when you have traction on that side of the equation, add your consumer biz. And it's always useful to know how to write code.