Didn't United try this on their short lived airline Ted? If I remember, it doesn't work very well, if only because many people travel together and take window and center and aisle, and they, quite reasonably, don't want to split up. In fact, you don't want to split up parents and children.

Then, you have the elite passenger problem, where frequent fliers, who can't always afford first class, board early to grab their seats and precious overhead baggage space, and they block the aisles.

All these ideas are clever, but they don't work very well.