Technology continues to change the way people shop.
This holiday season is expected to be a record-breaker for online retailers, according to Adobe's 2013 Online Holiday Shopping Forecast.
Internet sales are expected to jump 21 percent on Thanksgiving, 17 percent on Black Friday and 15 percent on Cyber Monday. Thanksgiving is on track to become a bigger total sales day than Black Friday within the next five years.
(Read more: Is Black Friday dead?)
Retailers with sites or apps optimized for mobile should see 20 percent of sales come from smartphones and tablets, the forecast said.
Mobile shopping also occurs while shoppers are in physical stores. The study found almost four in 10 people shopped online while in a store.