Shares of eBay Inc. (NASDAQ: EBAY) were down 9.1% as of 2:45 p.m. EDT Thursday after the online marketplace announced mixed quarterly results and reduced its full-year guidance.More specifically on the former, eBay's second-quarter revenue climbed 9.1% year over year to $2.64 billion, or near the low end of last quarter's guidance for a range of $2.64 billion to $2.68 billion.