• by Mark Walsh  @markfwal, November 19, 2012

Cyber Monday sales will rise 18% to $2 billion this year in the U.S. and Europe, with mobile playing a growing role in holiday buying, according to an Adobe Systems forecast. The projections are based on the software giant’s analysis of 150 billion visits to more than 500 retail sites over the last six years.

Bricks-and-clicks retailers are expected to see the biggest sales spike on Cyber Monday -- the Monday after Thanksgiving aimed at promoting online shopping. Business is expected to be up 450% more than on an average day, while online-only retailers will see a 200% gain, according to Adobe’s Digital Index 2012 Online Shopping Forecast.

It also predicts Black Friday will be the second-biggest online retail day this year, with sales growing 12% from 2011. Consumer Reports on Thursday suggested that tablets and e-books could sell out early on Black Friday, driven by promotions at stores like Walmart and Best Buy for devices such as the iPad 2, Nook Color and Kindle Fire.

In that vein, Adobe projects purchases via mobile devices will account for 21% of total online sales this holiday season, more than double the proportion last year. Tablets will account for 13.5% of m-commerce sales, while smartphones will drive 6.5%.

Black Friday is expected to be the biggest mobile shopping day of the year, with nearly a quarter (24%) of all online traffic to come from mobile devices.

Social media will play a big part in influencing holiday purchases, driving twice the amount of traffic to retail sites as last year. Visual bulletin-board Pinterest will see the biggest jump as a referral source, doubling from 7% to 14% of traffic to retail sites.

Despite widespread discounts offered during the Thanksgiving weekend, Adobe said the most competitive prices will actually be found online the week before Christmas, not Black Friday or Cyber Monday. The largest price reductions are expected to come on Free Shipping Day (Dec. 17), when many retailers offer free shipping to boost sales.

Adobe projects online sales that day will be up 12% from a year ago, especially since it falls on a Monday this year. Monday is typically the busiest online shopping day of the week. Adobe created its holiday index in part to promote its analytics services around big data.