As previously reported, Needham analyst Laura Martin downgraded TripAdvisor (TRIP) to Underperform from Hold saying instant booking's business model has lower ROIs than expected, its CPMs on mobile are monetizing at 1/3 the rate of desktop, and its strategic pivot from review site to booking engine is proving more expensive than hoped. The company cannot win a marketing war because even if it spends 100% of its 2017 projected revenue of $1.6B, this would be less than half Priceline's (PCLN) or Expedia's (EXPE) marketing, the analyst argues, adding that TripAdvisor's guidance for double-digit revenue growth coupled with flat to down EBITDA implies no incremental revenue is benefiting shareholders in 2017. Martin believes TripAdvisor looks expensive at current trading levels.