G: Cheese is right. You can use Google Analytics (its free - don't know why, most analytic places charge for the same information) to find out where and how many visitors come to your website/blog. Not only does GA tell where the visitor is from (state & city) it also tells which pages are accessed and for how long. A great free tool. Unfortuantely it is addictive to check and will burst your bubbles on how effective your marketing is.
From GA, found out that 15 people visited my sight over 2 years time from the ISC. More local organizations delivered more hits. Guess who got dropped? These were hits not sales.
GA is also good for some laughs. Just yesterday had 4 hits from the Ukraine. Haven't done any marketing in the Urkraine.