HuffPo holds it down

Top US social-networking site MySpace.com's audience was up 8 percent in March compared with March '07, but second-place Facebook's doubled, growing 98 percent from a year earlier, according to custom lists compiled by Nielsen Online, writes MarketingCharts.

LinkedIn increased its unique audience a whopping 319 percent from a year earlier, reaching nearly 7.9 million in March, compared with 1.9 million a year earlier - and surpassing Windows Live Spaces to take the No. 4 spot.

MySpace's unique audience totaled 60.4 million in February, more than double Facebook's 24.9 million.

Top 10 Blog Sites

Google's Blogger remained atop the blog site rankings with 38.7 million unique visitors, up 51 percent from 25.6 million in March '07.

WordPress was again up - an impressive 162 percent from March '07 - increasing its unique audience to 17.3 million.

Fifth-place HuffingtonPost.com also maintained its impressive growth: Its unique audience grew from 1.2 million in March '07 to more than 5.3 million - or 350 percent.

Meanwhile, AOL Sports blog The FanHouse burst into the top 10 with nearly 4.4 million unique visitors in March, taking the No. 6 spot.