Free hot spots are a Purple Cow.

Free hot spots pay dividends - Computerworld

"That means Wi-Fi service brings in more than $100,000 per year per outlet in return for an investment of about $8,000 per restaurant for wireless infrastructure, Wooley says. The largest continuing cost is backhaul to the Internet over 1.54Mbit/sec. T1 circuits, Wooley says. Since the cost of a T1 circuit varies from $300 to $700, depending on what part of the country you're in, he says Schlotzsky's would average those costs to induce existing franchisees to offer the service. (New franchisees will be required to offer free Wi-Fi, Wooley notes.)"