A Comscore survey of global visitors age 15 and older highlights how Facebook has grown by 270% in the last year, which would put it on track to being larger than MySpace by the end of this year. In North America it has racked up 68.4% of the total unique visits to MySpace’s 62.1%. Facebook only opened its APIs on May 24th, 2007.

Comscore said social networking behemoth MySpace.com attracted more than 114 million global visitors age 15 and older in June 2007, representing a 72-percent increase versus year ago. Facebook.com experienced even stronger growth during that same time frame, jumping 270 percent to 52.2 million visitors. Bebo.com (up 172 percent to 18.2 million visitors) and Tagged.com (up 774 percent to 13.2 million visitors) also increased by orders of magnitude.

Bebo.com has a particularly strong grasp on Europe, attracting nearly 63 percent of its visitors from that region, while Orkut is firmly entrenched in Latin America (49 percent) and Asia-Pacific (43 percent). Friendster also attracts a significant proportion of its visitors (89 percent) from the Asia-Pacific region.

“A fundamental aspect of the success of social networking sites is cultural relevance,� said said Bob Ivins, executive vice president of international markets. “Those doing well in certain regions are likely doing an effective job of communicating appropriately with those regions’ specific populations.