Google Analytics usually shows more visits than Webtrends does, for the same site, same time.
There are three reasons:
- If a visit starts before midnight and finishes after midnight, Google Analytics counts two visits. Webtrends counts one visit.
- If a page view happens in the middle of a visit that has a different campaign (organic search, paid search, or any hit with utm_campaign= in it), Google Analytics counts two visits. In other words, if a visitor who has your site open in one tab, then uses a campaign or search link on another tab to come to the site separately, Google Analytics considers that second action the start of another visit. The same thing happens if the visitor backs out of the site then returns via another search or campaign. In all the above, Webtrends counts one visit. (Note: these assume the visitor is moving around with no gaps of 30 minutes or more.)
- If you have WT or GA tags on two or more domains, Google Analytics will start a new visit when you cross domains. The exception is when the sites are linked and the links have been specially coded to transfer a Google Analytics visitor ID. Webtrends counts one visit. The exceptions for Webtrends are Safari (and soon Firefox, and maybe eventually other browsers), or any situation where third party cookies are not accepted.
If you know of any extra wrinkles to this or other reasons for the higher visit count in Google Analytics, let us know!