"Now that consumers have product details, price comparisons and reviews available instantly at their fingertips, shoppers complement what they’re seeing on store shelves with what they can find on the web. This behavior isn’t just limited to high consideration purchases like appliances and electronics. In every industry we looked at, including household items, apparel, and pet care, more than 70% of smartphone shoppers use their phones in store to help with shopping. In fact, two-thirds of baby product shoppers compare prices on their phones in-store.
So what are shoppers using their smartphones for in stores? The research showed that phones were primarily used for:
Price comparison (53%)
Finding offers and promotions (39%)
Finding locations of other stores (36%)
Finding hours (35%)"
Source: Research from Google, published in a blog post, 9th May 2013
Full research here