Facebook is king but Twitter makes waves

Users spend more time on Facebook than any other social network site. Much more. But other sites are growing quickly, and experts say no social network is safely on top of the market. According to a report released Tuesday by Nielsen, Facebook users logged 13.9 billion minutes on the site in April. That compares to 5 billion minutes on MySpace, 300 million on Twitter, and 202.4 million minutes on LinkedIn. Time spent on Facebook soared 699% since April 2008, compared to a 31% drop in time spent on MySpace, which is owned by media mogul Rupert Murchoch's NewsCorp. LinkedIn's minutes grew 69%.