Pros
First and foremost, the best reason to work at TripAdvisor is the great people here. People work hard and take their jobs and careers very seriously, but also make time to have a lot of fun together. The intersection of travel and web 2.0 is an exciting business to be in. The company's fast growth (organic growth in the U.S. and internationally, plus recent acquistions of several other travel media companies) provides good opportunities for career growth. TripAdvisor works hard to maintain its entrepeneruial "start-up" feel in the way people work, but it has the size and profitibility to offer very competitive compensation and benefits. There is a good feeling of job stability and probably further growth even in the currently difficult economic enviroment.
Cons
Some "growing pains" as the company has doubled in size each of the last several years. What used to be a great feeling of knowing everyone in the company no longer exists.