Mobile is not longer a stand-alone element, mobile is part of the path-to-purchase.  Mobile shopper stats change so quickly, but these stats have increased substantially.

• 8 in 10 smartphone shoppers use mobile in-store to help with shopping
• Mobile search is a starting point - 82% of shoppers us search engines for browsing product information while in-store
• Shoppers who use mobile more, spend more in-store - frequent mobile shoppers who use their phones to help make purchase decisions spend 25% more in-store vs. the shopper that uses mobile phone occasionally.

Source:  Google:  Mobile In-Store Research