Traditional Brick & Mortar retailers have seen sales chiseled away over the past 10 years by a scrappy little sales channel called the Internet. This is a disruptive trend, and one that we all see. The smarter retailers saw this coming, and rather than conceding the war, the fought back. This is why even with the mega-success of Amazon, Walmart.com is right there fighting the good fight.
Now however, with the advent of the Smartphone, retailers asleep at the wheel will find that the online challenge has 'stepped up it's game'. I expect that within 5 short years, we will see even some traditional Brick $ Mortar retailers that obtain more than 50% of their sales via a Smartphone (and other mobile devices). For etailers, perhaps as much as 75%. If you're not already, you need to start immediately plotting out your mobile strategy.