Most modern websites have some kind of web tracking solution for
collecting information about visitors to the site, which is largely
used by marketing staff to make decisions to improve the site to
increase traffic volumes.
Google Analytics is the most popular analytics package available,
not least because it is both free and extremely powerful. Google
Analytics (GA) is found in use at around 57% of the 10,000
most popular websites - including the likes of New York Times,
Washington Post, Mashable and Twitter. For smaller websites, this
figure is even higher.
However much site owners think of it as an essential website
tool, Google Analytics is covered by the requirements of the EU
Cookie Law. This means the website owners must seek consent
for the use of GA, using tools like Optanon.
Google Analytics sets first party cookies
that site owners want to track. It sets four cookies automatically,
and a fifth via opt-in (this relates to sharing information about
your traffic with Google).
The good news is that Optanon makes cookie law
compliance for Google Analytics very easy.
Optanon will help you tell your visitors about
GA, and provide them with the ability to opt-out without having to
leave your site. All it requires is a slight change to how you add
Google Analytics into your pages, which is very easy for most
websites to implement. If you use Google Tag Manager, it is
even easier to use Optanon to control Google
Analytics, subject to user consent.
Optanon also provides you with some simple
language describing what analytics is - which you can use in your
with a single line of code. See how this works within our own
Most sites can rely on Implied Consent for Google Analytics
using Optanon. If a user chooses to
opt-out, Optanon uses a first party cookie to
remember your visitors' choice for 12 months.
However, for those countries where explicit consent is required,
Optanon enables you to get consent for Google
Analytics before the cookies are set.
The ICO has issued guidelines on how to interpret the new EU
Cookie Law. In the PDF document entitled "Changes to the rules on using cookies and similar
technologies for storing information" they say: "An analytic
cookie might not appear to be as intrusive as others that might
track a user across multiple sites but you still need consent.
Further advices and opinions on analytics cookies can be found
in the opinion published by the influential Article29 Working
Google Analytics sets first party cookie, however many accounts
have the opt-out setting active to "true" which Google allows to
anonymously track website metrics for the purposes of
"benchmarking". Google says this information is used to
categorize a website and show a relative performance line in visit
graphs. This shows how well a website benchmarks for that
The ICO guidance says: "If the information collected about
website use is passed to a third party you should make this
absolutely clear to the user. You should review what this
third party does with the information about your website visitors."
Therefore in the instance of "benchmarking" it is clear consent
must be achieved for a website to pass information to Google.
Website owners should probably also tell visitors that they are
sharing the visit data with Google for benchmarking purposes, as
part of their disclosure about how cookies are used.
For more on Google Analytics please also see:
The Analytics Crunch
Globally and in the European Union member states Google sets the
A persistent cookie - remains on a computer, 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.
__utmb Cookie & __utmc Cookies
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.
This is a standard 'grace period' in web analytics. Ominture and
WebTrends among many others follow the same procedure.
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. In tracking terms this Cookie is
perhaps the most important as it will tell you about your traffic
and help with conversion information such as what source / medium /
keyword to attribute for a Goal Conversion.
Google __utmv Cookie lasts "forever". It is a persistent cookie.
It is used for segmentation, data experimentation and the
__utmv works hand in hand with the __utmz cookie to
improve cookie targeting capabilities.