Digmen1 - 11:07 am on Jul 25, 2012 (gmt 0)
You can also check your site on Compete and Quantcast.
I find that for the sites I study all 3 services show similar results.
I have used Alexa for about 4 years.
I think it is fairly accurate for popular sites.
But for lowly ranked sites the data can bounce around A LOT.
There are now millions of websites out there.