<font face="Verdana, Arial, Helvetica, sans-serif" size="2">There are two reasons that AA and UA don't have as much of a problem with this. The first is that they have more seats up front. The second, is that they can overbook business class as long as seats are available in first.[/B]</font>
Although, the true money maker is British Airways, which overbooks the hell out of its first class cabin (at $5,600 a piece) on flights that preceed the rarely filled Concorde.