TripAdvisor Inc. (Nasdaq: TRIP), creator of the world’s largest travel website by some estimates (including its own), said Tuesday it bought Brooklyn-based web company Wanderfly to expand the social features of its popular travel recommendations and guidebooks.

Ever since TripAdvisor split off from its parent company Expedia Inc. (Nasdaq: EXPE), the Newton, Mass.-based company has been increasing its social networking-style features. Examples include Friend of Friend reviews of locales and deeper integration with Facebook Inc.’s (Nasdaq: FB) social network to offer services like localized recommendations.

But relying on Facebook alone to extend the reach of the brand may turn out to be insufficient. By acquiring Wanderfly, TripAdvisor is integrating social networking features within its own service, rather than just through an app on Facebook’s site.

"The Wanderfly team understands the value in social travel planning," Steve Kaufer, TripAdvisor’s co-founder and CEO, said in a statement Tuesday. "They're a great asset as we continue our developments in this area and I am delighted to welcome them to TripAdvisor."

Wanderfly’s central conceit as a travel site is that “everyone travels differently, so we all need different recommendations.” So far in its short history, the company's aim to offer personalized travel tips to users has made a small dent in the world of web-based travel services, an industry that is struggling as a tough economic environment results in fewer people traveling.

In February 2011, TechCrunch reported raising $1 million from private investors enthusiastic about its social recommendation service. At the time, the company said that it planned to use the new funding to expand its social features, which it did the following March when it redesigned its website with a Pinterest-like sharing service that allows users to “recommend, add photos, and save your favorite spots (map ‘em too!).”

Similar to a music streaming and file-sharing service like Spotify, Wanderfly now allows users to sign in with their Facebook account information and add friends whose travel progress they can track and comment on. The site also lets users make recommendations and post content about their own cities.

TripAdvisor shares rose 36 cents to $32.30 in afternoon trading.