EBay Inc. said today that it has struck a deal to acquire e-commerce and marketing services firm GSI Commerce Inc. for $29.25 per share in cash, totaling $2.4 billion, CNNMoney.com reported. The price represents a 51 percent premium over GSI’s closing share price on March 25, although it’s slightly below the stock’s 52-week high. GSI’s core business is providing e-commerce infrastructure — e-store technology, payment processing, fulfillment, marketing and customer service — for retailers, including RadioShack, Dick’s Sporting Goods and Toys “R” Us. The company also runs a licensed sports merchandise business operating that will be spun off and sold to a new holding company headed by GSI founder and CEO Michael Rubin, CNNMoney.com said.