I am building a freelance marketplace site with a WordPress theme. The idea is like fiverr for the free sharing economy. Online services will be provided by users in exchange for points that can be used to trade for another service just like the barter system. Apart from advertising, what revenue model options are available? Would this idea work at all?
Honestly, you're late to the game. I visited a website with the same business model last week. Also, in my opinion, WordPress wouldn't be the best way to implement such a site. Ideally, you'd have member logins and so forth, which are best handled some other way.
Yes, it's great to try a startup. And many projects have succeeded that weren't first to market. But don't forget to research existing solutions before reinventing the wheel. Look at how your competitors do it; and ask yourself how your site will compete, given their head start. Maybe it can, but look both ways before crossing the street.