Just over 12 months on from what was heralded as a major development in its drive to offer Instant Bookings for hotels, TripAdvisor has now inked a deal with Expedia Inc.

The Priceline Group was the first of giant online travel agencies to participate in the Instant Booking programme when it signed an agreement in October last year.

Instant Booking allows users to search and select a hotel on metasearch principles but secure the reservation on-site (the supplier or OTA retains the merchant of record rights).

TripAdvisor says the terms of the deal with Priceline Group, initially for Booking.com inventory and eventually for the Agoda and Priceline brands, were never disclosed but plenty of speculation at time suggested it was an exclusive one.

The new agreement marks a pretty big turnaround for Expedia Inc, which will be testing the partnership via its flagship Expedia brand in the US, after claiming in October 2014 that it would not participate and that TripAdvisor was one of its “less profitable channels“.

Still, two years is a long time in online travel and Expedia Inc’s Aaron Price, senior vice president of global marketing, says the partnership with TripAdvisor will give it a chance to “see how we can drive additional customer acquisition given the product and customer experience enhancements instant booking has made”.

TripAdvisor says there are currently 70 partners on the Instant Booking initiative, including a number of other online travel agencies (for example, GetARoom) and some of the major hotel chains such as Marriott, Accor, Best Western and Wyndham Worldwide.

Still, two-and-a-half years on from the original launch (and the start of a gradual global roll-out) of Instant Booking, TripAdvisor has consistently acknowledged that the project has faced some difficulties, not least with what president and CEO Steve Kaufer called a “monetisation leak”.

In its most recent quarterly earnings report in November, Kaufer said it was still “early days” and that the company was “exploring a full suite of marketing channels” to increase user numbers and awareness of the model.

He added:

“Brand re-education in an episodic category like travel is a multi-year process, and we remain encouraged by the positive trends we are seeing this year.”

Specifically on the new Expedia Inc deal, TripAdvisor’s senior vice president of global sales, Robin Ingle, says:

“Adding Expedia to the instant booking platform nicely complements TripAdvisor’s existing hotel inventory and helps users shop for a great deal on a hotel.”

The Expedia Inc-owned brand expected to participate in the US test is Hotels.com.