Google stated that it would abandon scanning the contents of your Gmail.
The new policy will be adopted in this year. Google has been utilized the words in your Gmail to optimize the advertisement which will be sent to you. It is unsurprising that this way has been criticized as an invasion of user's privacy.
Google's decision seems to have been partially based on increased number of paid corporate members. They have not got their Gmails scanned.
As well, Google can analyze each user's favor through scanning the history of YouTube and Google Search. They provide enough information about which kind of ads fit each user.
Google's policy change will not only attract users but also reduce the risk of being sued in the future. On the other hand, I wonder how this change will damage the quality of the advertisement, which is still the most primary sources of profit for Google.