Over a third of US spending in physical stores was influenced by mobile marketing, with more than $1 trillion in spending impacted by consumer interactions via smartphones and tablets.The figure doesnt take into account online sales, with a recent study by InternetRetailer.com showing that almost half of digital shoppers at the top 10 US retailers are now mobile-only.Both the figures come from a new whitepaper by Urban Airship, and demonstrate the importance of having a strong mobile engagement strategy, especially for retailers. Consumers now operate in an omnichannel world, and brands must meet growing expectations for seamless movement between devices and high levels of customer service and personalisation.Urban Airships whitepaper provides a comprehensive overview of digital engagement channels that operate on mobile, and how different channels can be employed to target key segments with increased efficiency. The whitepaper also provides insights into how the mobile customer journey differs from conventional models, and gives eight key steps that every brand can take to improve its mobile strategy and ensure better customer engagement via mobile.Click here to download Building Your Mobile Strategy: How to Boost Engagement & Achieve Mobile Growth for free.