What is the difference between New Visitors and Absolute Unique Visitors in Google Analytics?

Do I need an agreement with a website's visitors, if I use Google Analytics API to produce reports for the website owners?

• My company provides a traffic analysis service to various website owners that are already using Google Analytics to track their visitors. If the website owner grants me read-only report access to their GA account, do I need agreement from their visitors to crunch their data, or is the website owner responsible for this? I assume the website owner should have written in their "Terms of Use" for the website that their website may track data from their visitors and potentially share it with business partners from time to time. Thoughts?

• Answer:

  According to the http://www.google.com/analytics/terms/us.html, any website using Google Analytics has to abide to: 7. [...] You must post a Privacy Policy and that Privacy Policy must provide notice of Your use of cookies that are used to collect traffic data, [...] Later on it states that the website has to follow the laws and regulation of its country. Many countries have rather strict regulation on privacy. The website owner has to have a privacy policy clearly posted on their website when using Google Analytics. It would be easy to add a line in that privacy policy stating that data can be shared to third parties. I couldn't see anything in the GA ToS that explicitly said a service not being the one that collected the data in the first place couldn't use the data of the website. I am pretty sure many countries' regulations have something to say about that though. Then again, I'm not a lawyer. To do: Get the website a privacy policy, they need it to use Google Analytics. Have them state in the policy data may be shared with third parties. They have to make sure they are not violating regulation in their country/territory. You get an agreement with the website stating that they are responsible for informing their visitors about sharing their data, and you can not be liable for them not following regulation.