Again, this one is not compulsory technically as if you can turn this feature off for the sake of privacy Mozilla knows of. This collects your browsing habits and based on that, you will be suggested which advertiser websites in the New Tab. Personal data will not be sent to the advertisers of course and there will be no usage of cookies to do this advertising shit either.
This is kind of similar to what Twitter planned two years ago and the upcoming feature will be out in summer.
