Recently, I wrote about a Nielsen Online study which reported that 60% of Twitter users stop using the social network, micro-blog site within a month of joining. That study received a fair amount of criticism from the Twitter community. Tweeters believed that the study underestimated the size of their community because it failed to measure applications and other websites that feed into Twitter.
In response, Nielsen redid the numbers, taking into account more than 30 websites and applications that feed into Twitter including: TweetDeck, TwitPic, Twitstat, Hootsuite, EasyTweets, Tumblr, and many others.
The results, according to Nielsen's Vice President of Primary Research David Martin, "verified our initial findings: about 60% of people on Twitter end up abandoning the service after a month. The year-long retention curve looks very much the same as the one for just Twitter.com."