While I agree that is more realistic, I don't think $6.6 million is really better than $4+ million the next year (after another year of flat ticket sales barring some miraculous end to the season). Winning 3-4 games this season will not spike ticket sales.
$2 million is made up pretty quickly. When Hazell was hired, Purdue sold more than 3,000 new non-student season tickets. Purdue's average attendance that season (winning 1 game), was up 5,000+/game.
Using that math:
500 new season tickets in premium areas = $112,000
+ Legacy Fees (splitting half in $250 area and half in $100 area) = $87,500
Total: $200,000
+Four new suites sold + season tickets + donation = 150,000
+2,500 new season tickets in non-premium areas = $500,000
+500 new donors at JPC First Team = $100,000
That is nearly $1 million in revenue. And assumes minimum donations and does not include parking revenue or student ticket sales.
If you're selling single game tickets at $45/ticket (avg. ticket price this season), that is 22,000 tickets to reach $1 million. That is just over 3,000 tickets per game.
In simple terms, 3,000 new season tickets plus selling an average of 3,000 tickets per game = $2 million.