Earnings are flat, sales are slowing, and Tripadvisor stock simply costs too much.Tripadvisor (TRIP -11.09%) stock beat on second-quarter earnings but missed on sales last night, triggering a series of analyst price target cuts on the travel advisory services stock Wednesday morning -- and sending Tripadvisor stock down 11% through 10 a.m. ET.Heading into the quarter, analysts forecast Tripadvisor would earn $0.37 per share on sales of $504.8 million. Tripadvisor actually beat the earnings number, reporting ...