The retention rate actually seems relatively low as an absolute percentage, though the way it plateaus is interesting. I did an analysis of the retention of the

The retention rate actually seems relatively low as an absolute percentage, though the way it plateaus is interesting. I did an analysis of the retention of the oldest Slashdot users (http://www.kmjn.org/notes/early_slashdot_users.html http://www.kmjn.org/notes/early_slashdot_users.html), and it was much higher: about 70% after 2 years, rather than 30%. Took about 10 years to drop to 30%. Granted, that's for the earliest users, so retention rates are probably (much?) lower among later signups.