I use SexKey because it is the only AVS with which it is completely free for you to register. SexKey is an Age Verification system that was developed to restrict minors from entering adult oriented sites. SexKey Provides you with FREE access to thousands of the best adult sites on the net. Don't be fooled by those other services that make you pay over and over again just to prove that you're an adult. This is to verify your age.
Federal law states that a credit card holder is a valid adult.
You will never be charged for your SexKey membership. They are Verisign secure, and stake their reputation on keeping credit card details safe and secure.