eBay announced today that it has completed its acquisition of GSI Commerce, which was announced back in March. The deal was approved by stockholders on the 17th.

eBay acquired all outstanding shares of GSI at $29.25 pher share in cash, adding up to about $2.4 billion.

GSI Commerce will continue to operate as a separate business from eBay, and will be led by Chris Saridakis as its newly appointed president. He will report directly to John Donahoe, eBay’s President and CEO.

“We intend to lead the next generation of commerce innovation,” Donahoe said when the deal was first announced. “The acquisition of GSI, which offers the most comprehensive integrated suite of online commerce and interactive marketing services available, will significantly strengthen our ability to connect buyers and sellers worldwide. Combined with eBay Marketplaces and PayPal, we believe GSI will enhance our position as the leading strategic global commerce partner of choice for retailers and brands of all sizes.”

“While those are longer range goals that the combined companies are fast at work on – coming in today there was a noticeable difference already,” GSI’s Jose Mallabo said today on the GSI Commerce blog (also providing the following pictures. ” For the people sitting at the King of Prussia headquarters of GSI you didn’t have to read the release or this post to know the deal closed – you just needed to look up as you walked in.”

Some think the deal is key in eBay’s competition with Amazon in e-commerce, as GSI powers an impressive list of clients‘ e-commerce offerings. Clients include major brand like Adidas, Calvin Klein, Nautica, Levi’s, Toys “R” Us, HP, NFL, NBA, MLB, NASCAR, ESPN, Dick’s Sporting Goods, and many more.

In March, we ran an article from Rob Diana, who said, “This is the easiest way for eBay to get into ecommerce for larger brands without affecting their auction business. They get a known name in ecommerce and an excellent client list. In addition, they also get the warehouses and distribution facilities that GSI  manages for some of their clients. Yes, they have warehouses which contain either merchandise for their clients or merchandise that they own and sell through their clients stores.”

“This combination of things could make a huge business for eBay,” he continued. “In order to see why this is a good idea, you have to think of the possibilities. There is the obvious ability to start hosting major ecommerce brands. However, the other parts of the deal really make it interesting. eBay has its own auction site. Match auctions with “discount” items from the merchandise their clients sell and warehouses to distribute from. Very quickly, eBay could become an even larger player in the discount and used merchandise niche because they would own some of the product. Or they could enable the client stores to hook into the eBay auctions so that they can have their own outlet store and auctions.”

eBay completed the divesture of GSI’s licensed sports merchandise business and 70% of its ShopRunner and Rue La La businesses to a newly formed holding company led by GSI founder and former CEO Michael Rubin.