With over 25 million registered users and 12 million completed projects, Freelancer.com is one of the most popular online marketplaces. It operates on a commission and monthly membership fee model: both the employer and freelancer pay an hourly or project fee, with the commission varying depending on the membership level of both parties. One limitation is that freelancers can only submit up to 8 proposals in a month before they’re forced to upgrade to a paid account, which may be a deterrent for freelancers just starting out.