Jon Gibs, vice  president, media and agency insights, Nielsen Online, notes  "We have seen major growth in Facebook... and a subsequent  decline in MySpace.  Twitter... (is) perhaps  changing the outlook for the entire space... regardless of how fast a site is growing... it can quickly fall out of favor with consumers... (who) are willing to pick up their networks  and move them to another platform... at a moment's notice."

April was the fourth month in a row that Facebook held the top  spot in both unique visitors and total minutes, but Myspace has been winning in online video with 120.8 million video streams.

Myspace visitors spent 384 million minutes viewing video on the  site, with an average of 38.8 minutes per viewer.  In comparison, Facebook visitors  spent only 113.5 million minutes viewing video in April, with an average of 11.2  minutes per video viewer.

Gibs concludes, "... maybe the better question to ask is who does each site reach, not who is  'winning'... and how are they building for the  future to maintain the loyalty of their visitors, who to this point have shown  little long-term loyalty to any specific platform."

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