Each time your help, shop, buy, sell on Protosbay you get experience. Each amount of experience you have gained is reflected in your level.
Ways you can obtain experience and level up is by:
You can also lose feedback by:
Trust levels are obtained by vendors by holding an escrow with the site in-case of an incident. They help verify the vendor is serious and can help build trust at low levels. A vendor can give up the badge and receive there escrow back. It is optional for a vendor to obtain a trust level.