Welcome to the crazy world of web analytics. If you're reading this FAQ you've probably already realized that different statistic packages may report different measurements. In fact if you looked at your stats in 10 different programs you may see 10 different sets of numbers. So why the difference in numbers? Perhaps the most common reason is the time zone setting. Raw logfiles are often stored using GMT time. When they are analyzed by the statistics software it will convert GMT time to a local time zone. The local time zone may be the same time zone as the server or it may be set specifically for your site. By default our stats program is configured to report in Pacific Time but upon request we'd be happy to change the time zone for your stats.

Beyond the time zone it is important to note that each program defines their metrics slightly differently and these small changes can result in numbers that very greatly from program to program.

Let's look in detail at categories that we hear about most often:

Visits / Sessions

Visits or sessions are defined as a series of clicks on your site by an individual visitor during a specific period of time. A session is initiated when the visitor arrives at your site, and it ends when the browser is closed or there is a period of inactivity.

Some web analytic programs time out after 15 minutes of client inactivity. Some timeout after 30 minutes. If a client sits idle for 20 minutes and then visits your site again this may result in some programs recording this traffic as a new session while other programs will consider it the same session.

Some programs require a page hit to register a session. This means the client must visit a known page type such as .html, .asp,. aspx. Other programs only require a hit of any file to record a new session. This results in some programs recording a new session if a visitor performs an activity such as downloading a PDF while other programs will not record this as a session.

Geographic Reports

Geographic reporting is another area that can differ greatly from program to program. Web logs record only IP addresses, the statistics program being used much convert these IP addresses into country information. Some statistics programs access external databases which have mappings of IP addresses to countries. Other programs only look up the domain name associated with that IP address and return the associated country. For example your IP address may belong to a US based computer but the domain name for that computer may be mydomain.ca. Programs that operate by domain lookups only will record this as a session from a Canadian visitor. Programs that access an external database of IP to country mappings will most likely return this as a US visitor.

Downloads

Downloaded files such as PDFs and EXEs may also be counted differently by different stat packages.

For example when a visitor views a PDF file the PDF reader may partially download the file, or download the requested portion of the file on a page by page basis. If your PDF file has 10 pages it may be downloaded 10 times by a single visitor's browser, 1 download for each page. Some stat packages will recognize this activity and record this as a single download while others will record this as 10 downloads.

Browser Type

If a statistics program isn't aware of a particular browser type it may reported as unknown or possibly incorrectly reported as a different type of browser. New browsers are released all the time, if the statistics package being used isn't up to date this is a common error.

Search Engine

Most statistics programs include a search engine report. Some programs only report for certain search engines while others will dynamically try and determine the search engine.

Referral Reports

Your statistics program should be configured to automatically exclude your own domain(s) and IP addresses from your referral reports. Not doing so may greatly inflate your referral numbers. Some statistics programs may automatically do this to a certain extent, others may need to be configured.