Germany's Trivago (NASDAQ: TRVG) -- the last major online travel site to go public -- has shed 70% of its value since peaking four months ago, hitting yet another all-time low on Monday. Wall Street cooling on travel sites including Priceline and Ctrip hasn't helped, but the deep wounds at Trivago and TripAdvisor stem from model-specific lapses . Despegar's uninspiring performance in 2016 was the handiwork of a drop in air ticketing revenue, something that isn't a surprise given how socioeconomic and inflationary factors have curbed international travel in some Latin American countries.