Alexa ranking isn't really that accurate. And sometimes a website has a high Alexa ranking based on traffic from one day. I recall a few websites I had in the past that got Stumbled and received a lower Alexa ranking. However the daily traffic I was getting didn't match up with that. I also had websites that didn't receive any traffic and had an Alexa ranking of about 1,000,000 and other websites that received about 100 uniques a day that had an Alexa ranking of about 5,000,000
Was 97,000 a couple of months back however, it's gone down to about 150,000 now although my traffic has increased. Alexa is complete bollocks.