Since favorites are already anonymous and promotes act as a public favorite, my suggestion is to rename 'favorite' to 'like' and leave promote as it is, since it's a fresh terminology that gives off a vibe of originality yet retains the common favorites function from other sites. This would also have more people use the two functions, as the difference is a bit confusing right now, and maintain the great idea you guys had of seamlessly merging the function of favorites and shares commonly found in social networks.
Keeping the promotes will also fill the place of an unnecessary 'dislike' button as well, which is easily abused and the difference in feedback is still given by likes/upvotes.
P.S. I know this could have easily been put as an answer to a relative ticket, but I felt this suggestion to the site was specific enough to have its own thread!
Customer support service by UserEcho