Facebook’s US visitor growth slows to 5% as market penetration hits 71%

Facebook’s year-on-year growth in unique visitors in the US has slowed to just 5%, according to new figures.

According to market research figures from ComScore, published in the Wall Street Journal, the number of unique visitors in the US has grown by 5% to 158 million, with market penetration reaching 71% of US internet users.

This marks a significant deceleration from the 89% year-on-year growth the website recorded in April 2010 and 24% growth in April 2011.

The figures point to a potential tipping point for the recently listed social network as it reaches saturation in terms of its potential user base.