If you fly domestically with any frequency, even 3x-4x/yr, and would be interested in how to game AA's system domestically, holler and I would be happy to go through all of it again. It only works if you travel abroad annually though, as you need 4 flights (individual, so A->B with a layover is 2, so r/t w/ a layover each way makes 4) on either BA metal, or a codeshare, and BA can't sell domestic US tickets as a codeshare. But, the end game is free, full lounge access (yes, even Flagship Lounge, and even if only flying domestically) as well as some other stuff. But the above is the big thing. Why? Because when you get in a bind, the agents in the lounge are far better equipped to fix it, and fix it well. They have user permissions well above the agents available to the plebs. Plus, you know, self-pour at the Flagship Lounges kinda rocks.