MEDIAPOST — Mobile social networking is gaining ground. As of January, 17.1% of U.S. mobile subscribers went to a social networking site or blog compared to 13.8% in October, according to new data from comScore MobiLens. The Web measurement firm last week reported Facebook and Twitter have both seen triple-digit traffic growth on the mobile Web in the last year, reaching U.S. audiences of 25.1 million and 4.7 million, respectively. (MySpace's mobile site dropped 7% to 11.4 million.) Highlighting broader growth, Facebook recently announced cracking 100 million active mobile users worldwide...

MEDIAPOST — Facebook and Twitter both saw triple-digit traffic growth on the mobile Web even as MySpace lost ground to its social networking rivals among cell phone users in the last year. Facebook's U.S. audience on the mobile Web more than doubled to 25.1 million in January 2010 compared to a year ago, while Twitter's grew fourfold to 4.7 million, according to data released Wednesday by comScore. By contrast, MySpace's mobile Web audience declined 7% to 11.4 million during the same period...

INSIDE FACEBOOK — Nielsen is the latest web measurement company to release a review of social networking traffic in 2009, and most of the results aren’t too surprising:  Both the number of users to social networking sites and the amount of time they spent increased substantially, with Facebook leading the way. Here’s our quick take...

NIELSEN WIRE — The Pareto principle, more commonly known as the 80/20 rule, is the idea that roughly 80 percent of activity will be accounted for by 20 percent of the participants. Vilfredo Pareto’s initial observation at the start of the 20th century, that 80 percent of Italy’s land was owned by 20 percent of the population, has become a common rule of thumb in business, but does it hold up when tracking activity for the U.K.’s most popular social networks? To see if it does, we equated activity with ‘time spent’ to reflect who is posting or consuming content...

EMARKETER — While Q3 2009 data showed e-mail on top for content-sharing, February 2010 information from social optimization platform Gigya points to Facebook as the Web’s top social sharing hub. Almost one-half of article links, videos, photos and other content shared via Gigya’s widgets are posted to Facebook, with another 29% broadcast through tweets...