eBay is launching virtual stores called “shoppable windows” this month that the e-commerce company hopes will help retailers generate more sales from their existing physical store networks. The first four of these screens will open from June 8 through July 7 in busy parts of New York City, such as the lower east side and Soho. They will sell 30 items from Kate Spade Saturday, a new fashion brand launched this year by apparel retailer Fifth & Pacific Companies Inc. eBay set up a window display in New York City in late 2011, but those storefronts did not let shoppers order products on the screen. The new screens measure about 9 feet across and 2 feet (0.6 meter) high and will appear on the front windows of closed stores.