Morning rush volume is most of the business
Walk in at 6am on a weekday. Donut shops live on the 5am–10am rush of commuters, construction crews, and early-shift workers. If your visit at 7am sees only three customers, the business has a problem the seller hasn't disclosed. If you visit at 7am and there's a line out the door, the operation is real. Verify with at least three weekday morning visits before signing an LOI; afternoons and weekends don't tell you the story.