Annual membership in the PTA gives you perks on both a national, state, and local level. Being a member gives you a voice to vote for activities, events, and how PTA money is spent.
Becoming a member no way obligates you to volunteer. Keep in mind that our many events and activities can only happen with the physical support of volunteers however! Book Fairs, Field Day, Holiday & Spring Socials, Trunk or Treat, Pancake Breakfast, etc. all require people to make them happen.