Back in April of this year, the world was introduced to the Apple Watch. It's been four months since it was launched, and the travel industry now has a better idea of how the Apple Watch and other smartwatches are being used for travel – and who's using them.

Although Apple is yet to publicly announce the sales figures of its watch, some analysts – according to an article on Tnooz – estimate that in 2015, between 15 and 30 million Apple Watches will be sold.

But what kind of traveller uses a smartwatch? According to Euromonitor, multi-device owners are more likely to purchase wearables. Those who travel with their smartwatch firmly on their wrist are using them mainly for personalisation, services, notifications and bookings.

In particular, smartwatches are being used for: boarding pass access; check-in; flight notifications; directions and maps; room service orders; and to unlock hotel room doors.

After all, it is beneficial for travellers to be able to quickly glance down at their wrist and see whether their flight is delayed or their gate has been changed; these kinds of real-time updates are very valuable to the traveller.

Likewise, travellers can briefly check their wrist for reassurance that everything is going smoothly and nothing has changed with regards to their travel arrangements or flight times.

As a result, the integration of travel services with wearable technology will encourage more frequent and relevant touchpoints with the traveller. This short and quick information is particularly attractive to Millennials, who want to know things without having to search for it, and business travellers whose time is often of the essence.

Looking even further ahead, Euromonitor predicts that we will witness the sale of nearly 250 million wearable devices in 2018, with sales estimated to increase from $8 billion this year to $20 billion in 2016.

Just a few years ago, most travel companies regarded wearables as a fad; they were considered a niche market, used mainly as a heart monitor, sleep calculator or fitness band. These days, according to Henry Harteveldt from Atmosphere Research Group, "Nearly four in 10 travellers can see a benefit of using wearables when they are travelling." Some 64% of business travellers plan to use a wearable within the next few years. This makes the smartwatch a very viable tool through which online travel companies can communicate with their consumer.

Only time will tell if smartwatches become travellers' second skins. Will your travel company be embracing the smartwatch as part of your digital strategy?