It is excellent platform for freelancers, there are some things to watch out for. First of all, ratings are everything. If you are not fully prepared to meet customer expectations, you may not want to advertise on Fiverr. Along those same lines, be very clear and detailed in your gig descriptions.
A second thing to avoid is the unrealistic expectations that often come with sites like these. Fiverr will be a helpful tool to help you fill out your schedule. However, it is unlikely you will make your entire living using just this site alone. You have to get out there and find work if you want to stay busy.