Online travel names sell off in response to TripAdvisor's (TRIP -16.5%) Q2 revenue miss, PCLN -3.9%. EXPE -3.9%. OWW -1.2%. During its earnings call, TripAdvisor noted international ad rates fell, and that efforts to improve "traffic quality" also took a toll. The company reiterated guidance for "high teens" 2012 revenue growth, but that's below a 21% consensus. Benchmark is worried aggressive search ad spending by travel agencies could be hurting TripAdvisor's search ad returns.