The counter is near the top of the right-hand column of the blog, at the bottom of a box that looks like the pic shown on the right. For tacticians hoping to land on the two millionth visitor spot, there's also a red icon on the left of the Digest screen that shows you how many people are currently on the site. Also, note that there has to be a 20 minute gap for the same IP address (the identifier for a particular computer) to be counted as a new visitor.
The 2,000,000th visitor may come and go unawares of this prize. If so, I'll send the book to the next closest after the two million mark. So if you're near, take a screen-grab and timing and try your luck.
You have read this article Announcements / Competitions with the title Free signed copy of The Rough Guide to Psychology for the 2,000,000th visitor to the Digest blog. You can bookmark this page URL http://psychiatryfun.blogspot.com/2011/05/free-signed-copy-of-rough-guide-to.html. Thanks!