Ready or not, retailers have to create a mobile commerce strategy. In the past 18 months, m-commerce has jumped from experiment to reality. Here are the facts:

—On any given day, 57.8 million American consumers access the web via mobile devices, according to the Pew Research Center.

—There are 112 retailers, 58 in the Internet Retailer Top 500, with 153 m-commerce sites and/or apps.

—North American mobile commerce sales will top $750 million this year, according to new data from emerging technologies consulting firm ABI Research.

—Retailers in mobile commerce report consumers are not just browsing or comparing prices, they’re buying—and sales are growing. EBay, for example, reported a whopping $380 million in sales through its iPhone app and m-commerce site for the first nine months of 2009.