The numbers are in from Hitwise and it shows that while Facebook may be a media darling, it’s MySpace that remains the most popular social networking service in the United States. According to Hitwise, MySpace controlled 73.82% of the social networking market in April, up 0.23% from March, compared to Facebook’s 14.8%. Hitwise monitors how 10 million US Internet users interact with more than 1 million websites across 165 plus industries.