Ads? Why? For business travelers it's definitely worth paying a subscription for.
Even as someone who rarely travels on business, I see immediate value. When I'm picking up someone from the airport I try to schedule it so I get there just after they leave baggage claim. This would save me a huge amount of time if I can predict that the flight will be late. Here in a sparsely populated state like MN there are many people who live so far from MSP (our main airport) that they essentially have to plan their entire day around driving to the airport. Arriving after a 3 hour drive just to find that the flight is delayed by 2 hours is a total waste of time for them.
Selling directly to users/corporations looks like the way to go.
EDIT: They charge for their mobile apps. Maybe something like this is better off being ad supported?