Cookies are small text files that are placed on your computer by websites that you visit. They are widely used in order to make websites work, or work more efficiently, as well as to provide information to the owners of the site.
Cookies can also be used for online behavioral target advertising and to show adverts relevant to something that the user searched for in the past.
A persistent cookie - remains on a computer for 2 years, unless it expires or the cookie cache is cleared. It tracks visitors. Metrics associated with the Google __utma cookie include: first visit (unique visit), last visit (returning visit). This also includes Days and Visits to purchase calculations which afford ecommerce websites with data intelligence around purchasing sales funnels.
These cookies work in tandem to calculate visit length. Google utmb cookie demarks the exact arrival time, then Google utmc registers the precise exit time of the user.
Because utmb counts entrance visits, it is a session cookie, and expires at the end of the session, e.g. when the user leaves the page. A timestamp of 30 minutes must pass before Google cookie utmc expires. Given__utmc cannot tell if a browser or website session ends. Therefore, if no new page view is recorded in 30 minutes the cookie is expired.
Cookie utmz monitors the HTTP Referrer and notes where a visitor arrived from, with the referrer siloed into type (Search engine (organic or cpc), direct, social and unaccounted). From the HTTP Referrer the utmz Cookie also registers, what keyword generated the visit plus geolocation data. This cookie lasts six months.
Google utmv is a persistant cookie which lasts for 2 years. It is used for segmentation, data experimentation and theutmv works hand in hand with the __utmz cookie to improve cookie targeting capabilities.
_ga cookie is used to uniquely identify users and expires after 2 years.
_gid cookie is used to distinguish users and expires after 24 hours.
_gat cookie is used to limit the collection of analytics data on high traffic sites and expires after 10 minutes.
_atssc, _atuvs and _atuvc cookies are used to count the amount of shares of content in social networks and expire after 2 years.
_auc cookie is used by alexa.com service to rank the website and expires after 1 day.
APISID cookie is used to measure the number and behavior of Google Maps users and expires after 10 years.
HSID and SID cookies contain digitally signed and encrypted records of a user’s Google account ID and most recent sign-in time. The combination of these two cookies allows to block many types of attacks, such as attempts to steal the content of forms that you complete on web pages. These cookies expire after 2 years.
NID cookie allows to obtain data on user’s preferences such as language, safe search settings and number of search results. This cookie expires after 6 months.
PHPSESSID cookie allows to store a simple message when a form is submitted that can be displayed on a different page. This cookie expires after each browsing session.
SAPISID cookie allows to measure the number and behavior of Google Maps users. This cookie expires after 2 years.
SIDCC cookie allows to protect users’ data from unauthorized access. This cookie expires after 2 years.
datr cookie allows to login using Facebook account. This cookie expires after 2 years.
lidc cookie allows to share content to Linkedin. This cookie lasts for 2 years.
loc cookie allows to identify approximate location of the user. This cookie lasts for 13 months.
mus and ouid cookies are used for social media sharing and behavioral advertising. These cookies last for 1 year.
personalization_id, twll, remember_checked and remember_checked_on cookies allow to share content to Twitter. These cookies expire after 2 years.
sb cookie enables Facebook social plugin. This cookie expires after 2 years.
ssc, sshs, uid, uvc and ssh cookies are used for social bookmarking. These cookies expire after 2 years.
Most web browsers allow some control of most cookies through the browser settings. To find out more about cookies, including how to see what cookies have been set, visit www.aboutcookies.org or www.allaboutcookies.org.
To find information relating to other browsers, visit the browser developer's website.
To opt out of being tracked by Google Analytics across all websites, visit http://tools.google.com/dlpage/gaoptout.