Nothing sells potential in game advertisers and game day sponsors like the usual 4-6,000 empty seats.
Why put the effort into understanding the financials and price points to sell seats?? Simply don't think it through, admire the 4-6,000 empty seats from the A.D.'s suite and go about your day. Maybe next time enough folks will step up and buy those tickets, then again, maybe not. Plus, charge the same amount for those upper level tickets as you do for those lower level tickets and deliver a significantly reduced overall gameday experience. F_ck'm . . . they should've given more money, or bought their tickets earlier.
Marketing to a captured audience is simply far to time consuming as well . . . why pay mere pennies on the dollar to market to an additional 4-6,000 people as compared to what it would cost if they were spread like seeds in the wind??