Groupon (GRPN +7.8%)  jumps on news the company is officially launching its mobile card reader,...

|By:, SA News Editor

Groupon (GRPN +7.8%)  jumps on news the company is officially launching its mobile card reader, after months of trialing the product in the Bay Area. Groupon's rates for most swiped transactions are lower than those of market leader Square's. The has led the bearish Rocky Agrawal to think Groupon, which can cross-sell the reader to thousands of daily deals providers, has a chance. But Square, now on an $8B/year run rate, has other advantages, and Groupon is far from alone in challenging it.