Best Western is the first hotel chain to implement TripAdvisor Instant Booking on desktop, tablet and smartphone in the United States.

Best Western and Choice Hotels are the big-name hotel brands that have been participating in TripAdvisor Instant Booking, but the pace of signing up additional chains has been slower than TripAdvisor expected and some of the hotels are confused about the feature.

That’s the view of TripAdvisor CEO Steve Kaufer when talking about Instant Booking, the feature that enables consumers to book a hotel without leaving the TripAdvisor experience as a hotel brand or online travel agency processes the booking, provides customer service and fulfillment, and pays TripAdvisor a commission.

Kaufer says TripAdvisor approaches hotel chains and has to explain Instant Booking “is a little bit in between” a direct booking and an online travel agency booking for the hotel “and that causes a little more confusion on the part of the hotelier,” said Kaufer during TripAdvisor third quarter earnings call with analysts.

Part of the confusion is that hotels have to decide whether to treat the economics of TripAdvisor Instant Booking participation as they would an online travel agency or a direct booking, Kaufer said, and one reason for the relatively slow pace of implementation is that integration requires tech work by both the hotel and TripAdvisor.

7 Hotel Chains Lined Up to Join

Kaufer said six Instant Booking partners are live and 16 are pending, including seven additional hotel chains.

“The pipeline continues to grow but not as fast as we would like on the site,” Kaufer said.

Read MoreTripAdvisor Turns to User-Generated Content for Latest Advertising CampaignIn other news, TripAdvisor reported that nearly 50% of its traffic now comes from mobile.

TV Advertising

In addition, TripAdvisor reported that it plans to increase its spending on TV advertising in 2015.

The company spent $19 million on offline advertising in the third quarter, up from $10 million in the second quarter and $3 million in the third quarter of 2013.

Kaufer said TripAdvisor would likely expand the geographies of its TV advertising campaigns next year and hasn’t decided whether to increase the frequency/density of the campaigns in individual markets.

TripAdvisor officials noted that the number of clicks it is getting per consumer using its hotel metasearch product is declining, but the company chalked that up to seasonality.

For the third quarter, TripAdvisor saw its net income decline 3.5% to $54 million on $354 million in revenue, a 39% year over year jump.