He said that the company was "looking at" more actively upselling customers who had already booked a flight or hotel on Expedia with an activity." The company is also looking at making offers to guests while they are in a destination, via Expedia's mobile app. Expedia's Local Expert unit deploys many teams within destinations to offer on-the-spot activity sales. Strictly speaking, these are "offline" sales, equivalent to a call center, but they still contribute to Expedia's overall activities bookings. The half-billion-dollar gross bookings figure is in line with Skift Research estimates that TripAdvisor is the market leading consumer marketplace for activities at roughly four times the size of Expedia by inventory. Consumer-facing startups like GetYourGuide and Klook appear to be gaining traction fast.