I hope they make enough from it to make a good case for tracking-free advertising. (And not that they end up wishing they were a bit less 'privacy-centered'.)
Mozilla is a mismanaged shell of its former self.
After users widely complained about the disastrous launch of Firefox Android that stripped most of the useful features, a senior Mozilla developer sent out a tweet giving the middle finger to users. 
I hate that there are only two major web engines now.
Mozilla has been taking money for giving Google access to advertise to its users since at least 2004
It's not a perfect solution. But Mozilla moving away from being dependent on Google is the best they can do. And it can entirely be disabled.
Can be turned off by toggling `browser.newtabpage.activity-stream.showSponsoredTopSites`.