ClustrMaps is a hit counter that (i) shows you the locations of all visitors to your site on a thumbnail map embedded in your page, (ii) uses dot-clusters that scale up to huge numbers, and (iii) lets you store old maps in an archive. The advantage of ClustrMaps Pro is that you can embed the maps into your own site rather than linking to the ClustrMaps site for zoomed-in map details.
Dr. Maxwell’s critique of ClustrMaps:
I love the tool and the visitor data that can be obtained. You do need the Pro version ($1.99/month or $23.99/2 years) if you want to embed it on a page or comment on your website. However, I worked around that by adding the “Text” widget where I wanted it (bottom of the page for our website) and paste the “embed code” in the Text box when you place the widget. You get the “embed code” from the ClustrMaps website when you create your FREE account and your ClustrMap. Next, tell people about your website and watch the dots multiply!