AAA gives those passes to people who book through them. they are non transferrable and void if sold.
that being said many AAA employees have found a great market in selling these.
id be willing to bet 50% or more of the people who use them acquired them on Ebay.
Or by being getting them from goodwilled people on internet boards like this. Which is why those who LEGITAMETLY should be able to park there often can't--the lot is full when they get there.