The purchase gives TripAdvisor more travel inspiration tools that help users discover new trip ideas. Wanderfly, like some of its social travel competitors, moved to a more Pinterest for travel format earlier this year, allowing users to recommend places, add photos and save their favorite spots.

The acquisition makes sense for TripAdvisor. Medros said at Mobilize that TripAdvisor would like to develop ways for people to record their travels in journals and share them with others. And he said the company was also looking at ways for users to get more real-time recommendations from friends and strangers while on a trip. Wanderfly, which has raised $1.4 million to date, doesn’t do all of that but it’s a nice foundation for TripAdvisor to build upon. And TripAdvisor can use Wanderfly’s tools to enhance its mobile apps, something Wanderfly didn’t have.

It makes you wonder if other social travel sites will be able to survive as standalone businesses. As we’ve mentioned, it’s hard to be in the social planning and inspiration market when people just don’t travel that much. I’ll be interested to see what happens to other companies like GTrot, Trippy, Tripl, Tripbirds, Twigmore and even bigger names like Gogobot. It might be that some can survive but I’m doubtful they can all make it by themselves.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Social media in Q1: commerce and discovery dominated
• Startup growth and the new recruiting ecosystem
• The future of mobile: a segment analysis by GigaOM Pro

For example, I said I wanted to take four days at the end of this month to go somewhere “eco” and “outdoors” with “romance” for under $1,000 from San Francisco, and Wanderfly mocked up trips for me to Bishop, Calif.; Ensenada, Mexico; and Edmonton, Alberta. I’m not sure I want to go to Canada at the end of October, but maybe I’m just a weenie.

New York-based Wanderfly is one of a few new startups attempting to create a more human approach to travel. Like Hipmunk — the flight search startup that provides some incredibly useful interface tweaks on top of an Orbitz affiliate agreement — Wanderfly uses flight and hotel data from Expedia. It also mashes up local activity recommendations from content partners like Yelp, Lonely Planet and Not for Tourists, and if you connect with Facebook, your recommendations include seeing local friends and sharing your trip plans with them.

Even if you think of sites like Wanderfly and Hipmunk as just skins for existing travel booking providers, they often give a preferable and innovative experience. Whether or not they can become a real business, and avoid getting ripped off by the big guys, remains to be seen. Wanderfly was founded a year ago, has about 10 employees, and has taken under $1 million in angel funding (it’s currently raising an additional round), and has been in private beta for the last three months with 7,000 users. Co-founder Christy Liu said the company sees itself as a sort of Pandora or Netflix for travel, and hopes to increasingly evolve and personalize its recommendations based on user behavior and additional travel and content partners.

Related content from GigaOM Pro (subscription req’d):

• What Twitter Airfare Sales Tell Us About Real-Time E-Commerce
• Is Geolocation a Real Business or Just a Feature?
• Multiple Models for Social Media Businesses