The second quarter of 2015 has seen business and leisure mobile bookings increase, Travel Pulse reports.

Analysing North American markets, a study by TravelClick found that the rise of mobile has led to an increase in transient bookings (made by individual business and leisure travellers) in 25 major North American markets – across online travel agencies (OTAs), official hotel websites and global distribution system (GDS) channels – compared to last year's second quarter.

The TravelClick North American Distribution Review found that OTA bookings rose by 9.7% year-on-year; bookings through hotel websites increased by 5.8%; while through GDS channels bookings increased 2.2%.

Across all channels there was a 4.4% average daily rate (ADR) increase compared to the second quarter of 2014. The good news for travel agents is that of all the channels, it was the GDS channel which experienced the most growth in ADR, with a 4.9% rise.

On the other hand, when it comes to the GDS channel's share of transient rooms, this decreased from the first quarter of 2015 to the second quarter of 2015, from 20.6% to 19.3%. OTAs meanwhile saw their share increase from 14.6% to 16.4% - the highest increase in share among all channels.

John Hach, senior industry analyst at TravelClick, said: "Mobile bookings are increasing at impressive levels and we anticipate the trend continuing into the foreseeable future.

"It's not just millennials who are using their mobile devices to research and book rooms -- it's happening across all major consumer segments. Interestingly, the GDS continues to demonstrate growth, especially with higher ADR bookings."

According to TravelClick, "similar booking patterns" are anticipated during the third quarter of 2015. This prediction is based on reservations already on the books: transient ADR is up for all channels, showing a 4.7% increase.

Already, Hotel Direct bookings (comprising both calls made directly to the property and walk-in customers), are up 5.6%; GDS by 4.6%; OTAs have risen 3.9%; official hotel websites by 3.8%; and central reservation office (CRO) bookings are up 3.8%.

So-called "old school" booking methods appear to be losing steam. Hotel Direct and calls to a hotel's 800-number (the CRO channel) decreased by 7.2% and 5.6% respectively, compared to same period of 2014.