Adobe today released its Adobe Digital Index 2013 Online Shopping Forecast, which focuses on predictions for this year’s holiday shopping season, defined as the entire months of November and December.

In Europe, the company’s data analysis predicts 12% of total online sales will come from mobile devices, a 68% year-over-year increase. This growth greatly exceeds mobile holiday sales growth in the US, which will hit 14% of online holiday sales, or 40% YoY growth.

If these two growth rates hold the same for 2014, European mobile sales as a percentage of all online holiday sales will equal or slightly exceed US mobile sales. For the US, Adobe expects consumers to spend more online this holiday season, up 12% from last year, with the largest online shopping day, Cyber Monday (December 2nd), hitting $2.27 billion, up 15% from 2012.

The highest grossing online shopping day in Europe is forecast to be December 9th, where the daily sales will be 2.74 times the 2013 average daily online sales. The highest grossing week of online shopping in Europe is predicted to be from December 9 -13th. For the entire holiday shopping season, Europe will see a 1.42 times increase in 2013 average daily online sales.

"The rapid growth in mobile shopping across Europe should be a very clear signal to retailers that a sound mobile strategy is not a luxury, but a vital part of their future success," said Mark Phibbs, vice president of EMEA marketing, Adobe.

"While tablets have certainly stolen the mobile spotlight and often generate three to five times more online sales for retailers than do smartphones, in every European country we analyzed, retail transactions on smartphones are growing faster than retail transactions on tablets. While this phenomenon is certainly aided by the recent introduction of smartphones with larger screens, it’s a reminder to retailers that a mobile strategy must include smartphones and not just tablets."