I'm sure there are many other examples.
If you consider the Katy Trail in Missouri. There are a few sections that don't get a lot of use, but perhaps the length of the trail helps attract users. Around the St. Louis area, the beginning of the trail in St. Charles attracts a lot of people, many may stop in town for a little shopping too. And, then head down the trail, and Defiance, for example, I think has bike rentals, shops that sell ice cream and treats, a small restaurant, and etc, all receiving customers related to the trail.
Perhaps trickle-down economics too as their ice cream (custard?) is bought from elsewhere.
Marthasville also had a great ice cream shop on the trail. I didn't see a lot of riders heading out that far, but a few dollars a day can give a welcome boost to any business.
Plus the occasional bike shop along the route. Bed and Breakfasts?