How bad DO sites overstate their number of visitors?

ComScore just released its White Paper on Cookie Deletion. Cookies are little files that web pages access to save information in for marketing, analysis, analytics, and to assist with user experience. For instance, when you check a box to save your login information on a site, it’s typically saved in a Cookie and accessed the next time you open that page. What is a unique visitor? For analytical purposes, every time a web page sets