IBM reports that Thanksgiving Day online retail sales increased by 11% over last year’s level. Despite the double-digit growth, this is actually a steep drop-off compared to years past. In 2012, Thanksgiving Day online sales increased by 32% over 2011. The pace of growth has thus dropped to just one-third of where it was a year earlier. Is this a sign of soft Black Friday sales to come? We’ll find out soon enough. Browsing increased even more sharply than buying: North American retail web site page views peaked 43% higher than they did in 2012. And mobile platforms are becoming the engine of online retail growth — purchases originating from tablets and smartphones hit 38% of overall sales, up sharply from 31% a year earlier.