In the second quarter of 2016, total revenue declined 3% to $391 million, with the hotel segment (TripAdvisor's largest by far) declining 8%. The biggest reason? Click-based ad revenue -- which makes up more than half of total revenue -- fell 15% to $201 million. While this looks bad on the surface, keep in mind it's the strategic path the company has chosen to compete more directly in the travel-booking game. In coming quarters, TripAdvisor hopes this drop-off in ad revenue will be offset by revenue generated from Instant Booking. And since this revenue isn't realized until a customer completes a stay, that timing has the potential to make revenue results -- when compared against the previous year -- look worse for another quarter or two.