Shortly after its “Like” button began to produce data about what best “engaged” its users, Facebook developed algorithms to bring each user the content most likely to generate a “like” or some other interaction, eventually including the “share” as well. Later research showed that posts that trigger emotions––especially anger at out-groups––are the most likely to be shared.
FT has no such mechanism though -- you read whatever threads you read, and FT doesn't do anything to promote "liked" content, so the evils of the Facebook approach don't apply here.