I'm not a developer at Codeable, but I'm part of the Codeable team so I feel I can add some more info here:
On Codeable, the "freelancee" only gets to see the average bid, which means they can only select their freelancer based on their credentials and such, not by price. That's huge and solves one of the biggest problems facing conventional freelancing sites.
Yep, the main difference with other marketplaces (for example those you've mentioned) is that devs and designers are asked to quote only on tasks that they're 100% sure they're able to address. Plus, as clients only gets one price/estimate, there's no "bidding wars".
Codeable is not a freelancer free-for-all. Only a small percentage of applicants get accepted (less than 5%). This ensures high quality for people looking to hire, and also a healthy amount of potential available work for each freelancer.
More about that: all contractors are screened before acceptance and, if they're good, they have a 1 month "probation" period where our CEO and the happiness team look out for them, checking if they're responsive enough, how do they communicate with other experts and clients, and so on. After that period, if you're good, you're part of our (growing) family.
Also, we let new developers step in only when we think the workload is enough to ensure high-quality keeps being provided by all.
The subject of the AMA's average project only seems to be about a few hours long. This is big for me because I'd rather not get bogged down with month long projects.
That's totally up to the developer/designer: in the interview I did with Nate (and others), he shared that doing small tasks was his strategy, at least at the very beginning, to get some "street cred" and collect nice reviews. Other experts like him, do this to get tons of reviews and get money quickly, but it's just a strategy. On Codeable there are also many projects in the 5000K+ that appeal to different types of devs/designers.
What's cool seeing here is how small tasks, like in the hundreds bucks, naturally grow into 1500K - 2500K projects. And that's because the communication between the client and the developer improves along the way, letting the former know how a professional WordPress dev can really enhance his/her business, while the latter is able to show how good he/she is.