This. The like button all too often acts like the "echo chamber": you're going to go around in circles. Writing a good recommendation system is very hard, and i

This. The like button all too often acts like the "echo chamber": you're going to go around in circles. Writing a good recommendation system is very hard, and it gets harder as the number of users grows (because primitive algorithms will get more and more certain of their predictions, and diverge less and less from the favorites). Anyway, the service is called loc "serendipity".