This from Yahoo Tech!:
Today's Twitters are often tomorrow's quitters, according to data that questions the long-term success of the latest social networking sensation used by celebrities from Oprah Winfrey to Britney Spears.
Data from Nielsen Online, which measures Internet traffic, found that more than 60% of Twitter users stopped using the free social networking site a month after joining.
"Twitter's audience retention rate, or the percentage of a given month's users who come back the following month, is currently about 40%," David Martin, Nielsen Online's vice president of primary research, said in a statement.
"For most of the past 12 months, pre-Oprah, Twitter has languished below 30% retention."
San Francisco-based Twitter was created three years ago as an Internet-based service that could allow people to follow the 140-character messages or "tweets" of friends and celebrities which could be sent to computer screens or mobile devices.
Twitter, as a private company, does not disclose the number of its users but according to Nielsen Online, Twitter's website had more than 7 million unique visitors in February this year compared to 475,000 in February a year ago.
But Martin said a retention rate of 40% will limit a site's growth to a 10% reach figure over the longer term.
Martin said Facebook and MySpace, the more established social network sites, enjoyed retention rates that were twice as high and those rates only rose when they went through their explosive growth phases.
Both currently have retention rates of about 70% with Facebook having about 200 million users.