StatCounter has a nice tool to personalize the graphics you need. I have choosen a recent periode here and it shows the piek in the hits (a few days ago) quite nicely. If you need to show someone the results of a special posting of PR-campaing on your website, this is a great tool. If e.g. someone would write about this blog and would link to this site that would show up in such a gragh immediately. With the other tools installed you could find out the references of these extra hits and you could trace where the extra visistors come from. That is in fact how I discover if and how someone has written about this blog.
If something like I mentioned above happens, I will write you a report on how I use the installed startistical programs to find out the details. With the right tools one can find out quite interesting details about a site.