OK.. lets see some figures,
Licenced themes across 3 manufacturers in the 90's only. Manufacturers are BallyMidway...Williams... Gottlieb.
BALLYMIDWAY - 67142 LICENCED THEME SALES.......56840 NON LICENCED
WILLIAMS - 68774 LICENCED THEME SALES.........113019 NON LICENCED
GOTTLIEB - 14980 LICENCED THEME SALES....... 44600 NON LICENCED
For all 3 manufacturers totals are:
LICENCED ; 150896
NON LICENCED; 214459
Which makes non licenced themes outselling licenced by 63563.
I have not included redemption/ flipperless games in any totals and numbers are strictly from 1990 onwards which ignores titles like F14Tomcat which had great sales of 14502
But then again, they did make a crap film about pinball once so i guess they are all licenced eh?