Ya know, I've tried them on a few sites. Unless their traffic shows up as some unresolved list or something I never saw anything at all come from ouster.com. I did see my site listed there though. You can get the same things pretty much from your server log file and using a program like 123LogAnalyzer. Without having to add their code and graphics to your site.

Chilihost is right; it's good for sites on free hosting. But there are other counters that do the same thing that can give you the same info as them. PayCounter is another one that I've used that tracked where traffic came from. (Shows you the entry link where the person clicked from.)The only thing with those counter things is that unless it's on the top of your site, it may or may not track the visitor. It doesn't track them if it's not done loading when they click and leave the page.