The internet has become a great tool for learning and discovery. But, it can also be an echo chamber. It encourages people to group themselves together according to their interests. The result is that they end up only hearing from other people who think just like they do. Nothing could be more antithetical to learning.
Social media are good examples of echo chambers as well. Many people will follow you on Twitter for no other reason than the hope that you will follow them. Same with Facebook page likes. Same with Pinterest, YouTube, etc. No one reads anyone's posts, no one looks at anyone's videos. No one listens.
I belong to a music sharing website called, ironically, Reverbnation. Reverb is what you often hear in an echo chamber and this is a good example of one. Artists "fan" other artists in the hope of being reciprocally "fanned." There's not a lot of listening going on just fan building.
But, what good are followers, likes, fans, subscribers if no one pays attention? Same goes for learning.