The only reason I signed up for MyHeritage several years ago was the marketing hype about their new Theory of Family Relativity.   I waited and waited and finally after a year or two I was notified about one Theory of Family Relativity generated by their super-duper algorithm.  It said I might be related to a third cousin I had known about for years and had myself posted to my tree on MyHeritage at least a year before their algorithm discovered her.  I haven't received another Theory from MyHeritage since.   
They talk a good game at MyHeritage about the wondrous things their computers can do with their vast data, but for me at least they perpetually underdeliver.