I used freelance bidding sites a few times over the past 15 years. Freelance writing is a competitive, feast or famine career choice, and auction sites can look attractive during those “famine” periods. To be honest, I’ve never had much success with these types of sites. Sure, I’ve found work here and there. For me, freelance bidding sites aren’t the place to look for well-paying, long-term clients.
But this is just my experience. While I don’t recommend using these types of sites, I would recommend doing your research before signing up.