By getting membership, you not only support the organisation, but also protect yourself.  Membership fees primary go towards covering the cost of insurance that protects all members of the SCA.  Being a paid-up member also means that you can become an officer of a group, take on an official position such as a combat Marshal, and have responsibility as a member of an Event Staff.  Plus it means that attending events becomes cheaper for you.  Attending just 3 events will mean you get your membership fees back!

Membership means more fun!