Over one billion people used Facebook last Monday. This is first time the site has had this many visitors in one day. CEO of Facebook, Mark Zuckerberg, said it was important achievement for his company. He posted on his own Facebook profile that: "We just passed important milestone. For first time ever, one billion people used Facebook in single day." He said that on Monday, "one in seven people on Earth used Facebook to connect with their friends and family". He added that: "This was first time we reached this milestone, and it's just beginning of connecting whole world." Mr Zuckerberg also said connected world, "brings stronger relationships with those you love". Zuckerberg created Facebook in 2004, while he was student at Harvard University. website quickly became one of biggest sites in world. Today, it has nearly 1.5 billion users and Zuckerberg thinks that number will grow. In October 2012, he announced that Facebook had one billion users who used site at least once month. Three years later, site had one billion visitors in just one day. Zuckerberg said company needs to grow lot in countries where Facebook isn't so popular, such as in many African and Asian countries and some in Central and South America. Facebook has made Zuckerberg ninth richest person in world, at age of 31.