Website analytics

Website analytics is the study of the behaviour of website visitors.

In a commercial context, website analytics especially refers to the use of data collected from a web site to determine which aspects of the website work towards the business objectives.

for example, which landing pages encourage people to make a purchase.

Data collected almost always includes web traffic reports. It may also include e-mail response rates, direct mail campaign data, sales and lead information, user performance data such as click heat mapping, or other custom metrics as needed. This data is typically compared against key performance indicators for performance, and used to improve a web site or marketing campaign's audience response.
There are two main technological approaches to collecting web analytics data. The first method, log file analysis, reads the log files in which the web server records all its transactions. The second method, page tagging, uses JavaScript on each page to notify a third-party server when a page is rendered by a web browser. Both logfile analysis programs and page tagging solutions are readily available to companies that wish to perform web analytics. In many cases, the same web analytics company will offer both approaches. The question then arises of which method a company should choose.
The extensive use of web caches also presented a problem for logfile analysis. If a person revisits a page, the second request will often be retrieved from the browser's cache, and so no request will be received by the web server. This means that the person's path through the site is lost. Caching can be defeated by configuring the web server, but this can result in degraded performance for the visitor to the website.
With the increasingly popularity of Ajax-based solutions, an alternative to the use of an invisible image, is to implement a call back to the server from the rendered page. In this case, when the page is rendered on the web browser, a piece of Ajax code would call back to the server and pass information about the client that can then be aggregated by a web analytics company. This is in some ways flawed by browser restrictions on the servers which can be contacted with Xml Http Request objects.