Travel booking on mobile continues to grow as a popular channel for U.S. consumers and could soon become the predominate way travel is booked online, according to new research from eMarketer.

The company’s latest forecast finds that digital travel sales are expected to reach $189.6 billion in 2017, of which 40 percent is slated to be purchased on mobile. That’s about a four percentage point gain for mobile compared with 2016.

The research from eMarketer includes airlines, hotels, sharing economy services, cruises, and car rentals.

“Last-minute travel deals are helping to drive mobile sales, as consumers opt to book right away via their smartphones,” said eMarketer forecasting analyst Chris Bendtsen. “Consumers are booking more travel on mobile due to larger smartphone screens, easier mobile payment methods, and overall habits shifting to mobile. Also, airlines, hotels, and online travel agencies have made both apps and mobile websites easier to use.”

By 2021, eMarketer projects computer and mobile booking volume to be neck-and-neck in upcoming years. Mobile booking volume would soar to some $108.75 billion in 2021.

U.S. Digital Travel Sales by Device (in billions)
201620172018201920202021
Desktop/Laptop$115.58$113.77$111.96$111.28$110.91$110.94
Mobile$65.01$75.85$86.20$94.90$102.38$108.75
Source: eMarketer

The divide between smartphone and tablet bookings also shows a strong advantage for smartphones, likely due to their cellular connections.

In 2016, consumers making purchases on smartphones represented 81.2 percent of all mobile travel bookers. More mobile users are researching trips on mobile, as well; in 2017 140.3 million U.S. consumers are expected to research travel online and 101.4 million of them, about 72 percent, will do so on mobile.

Photo Credit: Mobile booking is gaining in popularity with U.S. consumers. In this September 25, 2015 photo, people wait in front of an Apple store in Munich before the worldwide launch of the iPhone 6s. Matthias Schrader / Associated Press