Hits,Visits and Visitors
Hit:A request by a browser for a file, or,technically, a user’s click on a link and theresultant file transfers initiated by thebrowser. An HTML page usually has sev-eral images on it; when a user enters aURL or clicks on a link, the browser firstretrieves the HTML page itself (the for-matted text) and then scans it for files ithas to retrieve to display on the page.Separate requests for those images are ini-tiated simultaneous to the display of thetext portion of the page. A typical page,like Adobe Systems’s home page, mightresult in eight or nine separate requests - one for the HTML page and the rest forimages. Each of these requests is a hit.
Visit:A unique browser from a uniquelocation generating requests on a site(browsing or surfing) over a discrete pe-riod of time. Typically, Web producersbound visits on either end, so that if aspecific location and browser doesn’t showup in their log of requests for, say, 30 min-utes, the next appearance is a unique visit.
Visitor:A unique user. Identifying usersis done in several ways that vary from sim-ply using a cookie to requiring user registration. If youknow the visitor, whether by name or bycookie, you can do further analysis to know how many times that visitor comesto the site, where he or she goes, and soforth. This makes some people’s skincrawl; these users would prefer to beanonymous. But some Web sites use thiskind of information—with the user’s per-mission—to create profiles and custom-tailor information and services to them.
Cookie:A persistent bit of information,stored on the user’s local hard drive, that iskeyed to a specific server (and even a filepathway or directory location at theserver) and passed back to the server aspart of the negotiation that takes placewhen the user’s browser again crosses thatspecific server/path combination. Cookieshave been portrayed as invasions of pri-vacy, but the truth is that you can’t use acookie to retrieve information about auser. You can use it only to record whethersomeone previously visited a site, andwhat that particular user’s viewing behav-ior is. This is done by storing small codesor tokens that can be arbitrary (a sequen-tial or random number that’s unique) ormapped to information provided by theuser. The Navigator browser, according toNetscape’s specifications for it, will storeonly 4,096 bytes in a cookie, and only 300cookies overall (a maximum of only about20 per site), before dumping the informa-tion in first-in, first-out fashion.