This is the 3rd time someone has posted something like this (once by the same submitter http://news.ycombinator.com/item?id=880575).

It's a fairly useless metric to look at second hand reports of twitter's website traffic. If you have a bump in new users they would naturally use the website, as some of them left and the users who stuck around learned how to use 3rd party clients you would see a drop in website traffic.

Now does it signify that twitter isn't picking up new users at the same pace, perhaps. But when you think about the last 12 months I am not sure how they could sustain that pace (between Obama, Oprah, etc).