To infinity and beyond: Airbnb books 10M guests in its castles, cabins, and couches

More than 10 million people have stayed in Airbnb homes to date.

This is a long way from the company’s early days when the founders hosted people on air mattresses in their apartment and basically went door-to-door to get traction.

How far they’ve come.

Airbnb revealed its 2013 growth stats today, and expects New Year’s Eve to be its biggest night yet.

Over 6 million guests stayed on Airbnb in 2013, and 2 million of them were American. Travelers and hosts hail from over 175 countries, and Airbnb added 250,000 properties in 2013. It now lists over 550,000 properties worldwide.

Airbnb is a global marketplace where people can list space in their homes for rent. Listings range from couches to castles, and provide travelers with a hotel alternative that offers local flavor.

The site now features 350,000 hosts. In 2013, 175,000 people hosted a guest on Airbnb for the first time.

Airbnb made a big push this year to expand its support for hosts, in an effort to maintain a certain standard of quality. The company unveiled a number of new features and services in November, with a heavy emphasis on “hospitality.”

The latest mobile app includes more robust features for listing properties, as well as a superhost program for “extraordinary” Airbnbs, and tips for new hosts. Many people who become hosts are also guests and vice-versa, and one is often the gateway for the other.

Airbnb has experienced the kind of growth that entrepreneurs and VCs drool over. It completely disrupted the way people think of travel accommodation and managed to create a genuine community around its marketplace — although not without regulatory battles.

Mobile was also a big area of focus for Airbnb this year.

VP of Engineering Mike Curtis told VentureBeat that the team went from 2 iOS engineers to 13 mobile engineers this year and rebuilt the mobile apps from the ground up. He said 56% of travelers on Airbnb check the app while on their journey, and in 2014 the company is interested in bridging the online and office experience.

This means encouraging travelers to engage with Airbnb during the meaty middle part of their trip, no only before when searching and booking, and after to write reviews. The new “Stories” feature where travelers and hosts can share their personal experiences is a step in this direction. Curtis also hinted at plans to introduce more “complex services,” like helping you navigate a new city.

Airbnb’s biggest night so far happened over the summer, when 175,000 people were staying in Airbnb listings. It expects to surpass that this New Year’s Eve with 250,000 guests, which is double from last year.

The most popular destinations, unsurprisingly, are sun and ski locations, with Miami, Rio, Bali, Lake Tahoe, Strasbourg, Aspen and Vail ranking highly.

Airbnb has raised $326 million in venture capital over the years and is valued at over $1 billion.