A web counter or hit counter is a computer software program that indicates the number of visitors, or hits, a particular webpage has received. Once set up, these counters will be incremented by one every time the web page is accessed in a web browser.
The number is usually displayed as an inline digital image or in plain text or on a physical counter such as a mechanical counter. Images may be presented in a variety of fonts, or styles; the classic example is the wheels of an odometer. The counter often is accompanied by the date it was set up or last reset, otherwise it becomes impossible to estimate within what time the number of page loads counted occurred.
Some websites have been known to offer prizes to the visitor who makes the web counter roll over to a specific number. Such an event is known as a kiriban.
One of the more recent SEO spamming techniques, companies pay to have their site listed in the html code of a free hit counter. Thus when a user puts it on their page, a small link will appear at the bottom and can be a quick way for sites to accumulate inbound links. This is often performed by sites in very competitive web fields like online gambling and even asbestos litigation.
Google recently removed a number of high ranking mesothelioma sites that had been using counters from the top results.[1]