Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
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This is one of the four main cookies set by the Google Analytics service which enables website owners to track visitor behaviour and measure site performance. It is not used in most sites but is set to enable interoperability with the older version of Google Analytics code known as Urchin. In this older versions this was used in combination with the __utmb cookie to identify new sessions/visits for returning visitors. When used by Google Analytics this is always a Session cookie which is destroyed when the user closes their browser. Where it is seen as a Persistent cookie it is therefore likely to be a different technology setting the cookie.
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This cookie is set by Google Analytics. According to their documentation it is used to throttle the request rate for the service - limiting the collection of data on high traffic sites. It expires after 10 minutes
This is one of the four main cookies set by the Google Analytics service which enables website owners to track visitor behaviour measure of site performance. This cookie identifies the source of traffic to the site - so Google Analytics can tell site owners where visitors came from when arriving on the site. The cookie has a life span of 6 months and is updated every time data is sent to Google Analytics.