While Twitter is the latest Internet buzz word the site might not be as successful as many would believe.

Latest figures show that there are more than seven million unique visitors to the site this February compared to 475,000 the same month a year ago. But Nielsen Online revealed that 60 per cent of users stop using the free website just a month after joining it.

Nielsen's David Martin said that there simply aren't enough new users to make up for defecting ones after a certain point and the site is likely just to fold over time.

In contrast the last 'big thing' Facebook and MySpace has managed to keep 70 per cent of their fans. Martin warned that unless more users continue with the service after they join, Twitter's days could be numbered.