Complex sentence: By October 2013, Airbnb had served 9 million guests since its founding in August 2008, and in December 2013, the company reported it had over 6 million new guests in 2013, and nearly 250,000 properties were added in 2013.
Split into simpler sentences: By October 2013, Airbnb had served 9 million guests since its founding in August 2008. In December 2013, the company reported it had over 6 million new guests in 2013, and nearly 250,000 properties were added in 2013.