Yesterday, The Silicon Valley Insider reported according the Nielsen 60% of Twitter users quit after the first month. While over half of Twitter users fall off after a month, social networking services such as Facebook and MySpace have much strong retention rates.
They do not seem to want to give much weight to these numbers by quoting MediaMemo’s Peter Kafka:
It’s worth noting here that Nielsen is likely overstating the churn because it is only measuring visits to the Twitter.com URL. The majority of Twitter use happens away from the site, on mobile phones and apps like Tweetdeck, and it’s theoretically possible to never visit Twitter.com after you sign up.