It is a conundrum. Needing to get folks in, but also needing to make money.
I just checked the two closest shops. One offers open sewing for six hours mid day twice a month for $5. No food or instruction/assistance/demo is offered.
The second shop, which opened a few weeks ago, offers open sewing once a month from 6 PM to midnight and charges $15 for pizza and soda; snacks and dessert may be brought in to share. Although there is no formal instruction or demo, "an experienced quilter will be on hand."
The second shop also offers a once a month gathering for socializing and show and tell, no sewing involved. May include a demo of a technique or tool. As this shop's owner still works a full-time job, this is also held in the evening. Door prizes will be given; if you bring in show and tell you get extra chances for the door prize. These sessions cost $5/month.
Personally, I'm more likely to spend the money for time dedicated to sewing, understanding that there will also be socializing involved.
While I realize you were looking for feedback to specifically help this owner increase traffic, other options for people who want to sew without paying include sewing bees/small groups in your home, library or community center. When groups are working on community service projects - quilts or lap quilts for the needy, pillow cases for children, etc., public spaces are often willing to let groups come in during hours that they are open at no charge. Our guild also has a sewing day once/month that there is no charge for other than what is paid to the church for use of their all for our guild meetings.