Airbnb released its comprehensive summer travel report and it shows an impressive, almost staggering, growth. This summer alone, more than 17 million people worldwide have booked through Airbnb's home-sharing platform.

Not too long ago, in 2009, founders Brian Chesky and Joe Gebbia were just two roommates who couldn't afford to pay rent. They looked at what they had: their apartment, and decided to create a website where they offered their living room as a bed and breakfast. Their first customers were three people travelling to San Fransisco to attend a conference. 

Barely eight years after, Airbnb has become one of the fastest growing companies, encompassing 191 countries. From three guests, they have now booked more than 50 million people since starting the company.

The report showed that this summer's guests came from all over the world, travelling from 57,000 cities and a total of over 10 billion miles to their destinations. In perspective, that is enough for you to fly from Earth to Pluto and back again.

Here's an interesting fact they've discovered about their guests this summer: a significant number chose to stay in rather unique "homes." About 12,000 travelers stayed in yurts, 25,000 stayed in RVs, 13,000 chose castles, and 50,000 preferred boats.

An earlier report indicated why Airbnb's groundbreaking home-sharing system is so successful. Gene Sperling, former White House national economic advisor and director of the National Economic Council, noted that majority of Airbnb's hosts come from working, middle-class families. The hosts rent out their homes to help pay the bills. Sperling pointed out that the supplemental money earned by these families in the United States alone represents a 14 percent annual raise in income. Likewise, Airbnb's majority of guests also come from the middle-class margin, and home-sharing provides a symbiotic relationship among hosts and travellers.

Clearly, Airbnb is not slowing down. Other similar platforms like RoomiRentshare and Splacer have followed suit, making travelling and renting more affordable and accessible.