Are people buying more F (due primarily to lower F fares)? Sure. But it bears keeping in mind that perhaps the biggest impediment to 1K CPUs is that in virtually all instances, UA now holds off until T-24 to run sweeps. Just take a look at the waitlist T-96 and figure what would happen if UA were to run a sweep, vs. what happens at T-24, after those on the waitlist have had three days to watch the F cabin fill and ponder that discounted buy-up to F . . . .