Mobile traffic during the five-day start to what is typically the busiest shopping period of the year is expected to reach 56.9 percent of total traffic, up from 48.5 percent last year, according to IBM Watson.

And even though everyone who 'window shops' on their phones isn't going to buy, mobile sales are jumping too. Mobile sales are expected to account for 36.1 percent of online sales, up from 27 percent last year, according to IBM Watson Trend.

The bumps in traffic and sales come as retailers try to make the mobile shopping experience easier by improving their mobile apps and adding coupons and other deals. Shoppers also have gotten more comfortable browsing retailers' web sites as smartphone screen sizes have gotten bigger, making it easier for them to see photos of the items they want to buy. Digital wallets and apps that let shoppers store payment information are helping too.