Do understand that if Google is putting it up on its pages and also mailing every Gmail user - how big are the after-effects of the change going to be!!
The changes will come into force from march 31st.
Let me put this in simple terms : (using Youtube & Gmail)
When you read a discussion on buying shoes on your Gmail, you are served advertisements related to buying shoes online. These "contextual ads" are served based on the keywords in your mail chain.
So, with the new policy, if you have been searching on Google(and forgot that you are signed in) for 'something-secret' (which you don't want others to know) and immediately switch to Gmail with the same account, no wonder you might be shown ads based on the previous 'something-secret' search.Continued on the next page