The annual Digital Index Travel Report was released by Adobe earlier this month, providing details on the best times for booking flights and accommodation, the most popular destinations and the different consumer buying behaviours based on the device used, Hospitality Net reports. The research gathered information based on over 15 billion online visits to travel, airline and hotel sites in the US from 2013 to 2015; it also tracked over three million travel-related mentions on social media.

The report is renowned for providing the most comprehensive set of travel insights for industry professionals. It utilises data from Adobe Marketing Cloud and information from seven of the top ten airlines, eight of the top ten hotel chains and other major US-based travel sites.

Some of the key takeaways from the report centred on the changing habits of consumer bookings – for example, 20% of travel bookings were made using a smartphone or tablet, an increase of more than 6% compared to the 2014 report, with $1 in every $5 being spent via these devices. More travel companies are now looking to optimise their site for mobile use, or have recently done so.

In terms of how much is typically spent on travel, US holidaymakers are looking to spend a total of around $65 billion online for summer holidays this year. Just under a third of respondents said they believe they will be spending more on travel this year, at an average cost of $2,788. Whilst hotel prices did rise an average of 5% year-on-year, the report found that the cost of flights in fact decreased by an average of 4%.

Adobe created a list of the top travel destinations for 2015 based on data from social media mentions; it was found that Washington D.C. was the most popular US travel destination, whilst in Europe it was London, Paris and Rome that were the most popular.

It was also discovered that if looking for budget hotels, consumers are better off booking their trip one month before they wish to leave and seeking out rooms for $120 or less per night, as this can save them around 15% of their spend total. The time of booking was less important when looking for more expensive hotel rooms.

International flights should be booked 50 days before the leave date, as this can save consumers up to 32%. From 20 days prior to departure, airfare costs can increase significantly, at an average cost of +3% every day.

The report concluded that in 2015 travellers and holidaymakers are predicted to spend 7% more than they did in 2014 (two-thirds anticipate spending the same or more than last year). But despite mobile devices now accounting for 20% of total travel expenditure, not everyone wants to use their device while they are away: whilst on holiday, one-third are hoping to go somewhere where they are able to unplug and go offline.