The club did something like that (on a much smaller scale, obviously) with the open training and signing session at the start of the season.
It was great and much appreciated by me and my 3 kids, though more of a bonus for existing fans rather than recruitment of new ones.
(First time at Firhill for the youngest, might have got another new young fan).
Matchday reductions/promotions targeted at distinct groups, like the student day, or schools, youth groups, etc. seem more likely to yield new fans; early in the season a good idea.