I would say Zocdoc is the best example of B2C company tackling a regulated industry (healthcare) through a marketplace that I have come across. It does seem to

I would say Zocdoc is the best example of B2C company tackling a regulated industry (healthcare) through a marketplace that I have come across. It does seem to me that more startups are tackling the professional services layer with B2B solutions at this point. i.e. helping a lawyer process documents for discovery or allowing a doctor to more quickly process medical images for diagnosis. It seems to me, physician groups, law firms, accounting firms and architecture firms have all consolidated over the years, making B2B solutions fit better with status quo. I also think it is really hard for a marketplace to prevent future service transactions from occurring offline. As anyone who has used TaskRabbit knows, the first thing that happens is you usually get a direct number from the end provider and a lower rate to skip the marketplace in the future.