I think he's more icon than big-time director. You'll have to point me to any of his movies that have really racked up the bank. Has he ever had any movie break the $50 million mark?
A quick google of box office receipts.........
Date /Title / Studio / Lifetime Gross
10/31/08 Zack and Miri Make a Porno Wein. $31,457,946
7/21/06 Clerks II MGM/W $24,148,068
3/26/04 Jersey Girl Mira. $25,268,157
8/24/01 Jay and Silent Bob Strike Back Mira. $30,085,147
11/12/99 Dogma Lions $30,652,890
4/4/97 Chasing Amy Mira. $12,021,272
10/20/95 Mallrats Gram. $2,122,561
10/19/94 Clerks Mira. $3,151,130
Lifetime Gross Total (8): $158,907,171
Average: $19,863,396
Opening Gross Average (6): $8,214,710 (Wide Releases Only)