is a donation. Even if you have paid for a life membership, as long as the organization is doing what it is supposed to, most of us continue to contribute. If it goes off into left field, you stop giving. After that, your life membership costs them money because they still mail membership-related materials to you.
I know several NRA Life Members who have refused to send another dime because of the damage they see NRA doing. However, NRA still sends them a magazine, etc.
If you appreciate the work GOA is doing, and you can afford it, I encourage you to get a Life Membership, or at least buy new annual memberships for family and friends.