Let me explain Alexa rankings. First, they are NOT conclusive or verifiable to be accurate.
The only way to accurately measure global traffic to a site is to either be the site itself or control all the routing for the traffic reaching that site. Alexa can do neither. So the way they ESTIMATE traffic for Internet sites is by having users around the world install their Alexa toolbar on their browser. Alexa can then see the percentage of Alexa toolbar users that visit different sites on the Net, and make an ESTIMATION based on that for how much the rest of the Internet users view those sites. It's not a perfect system, but it gives a ballpark of various site's traffic.
So the numbers above say that of all the traffic that WAS visiting dailypaul.com about 22% of it has went away over the last 3 months.
Note: Alexa may have enhanced their data finding techniques, but the above is how they began operations.