This isn't a new phenomenon, when there were 3-4 major network outlets did the masses get "all the news" or was is pre-filtered by monied interests? It was most certainly the latter, the platform has simply changed.

This is something that is changing w/social media. Most users would rather have their own biases confirmed instead of challenged; because social media is just a way of monetizing a user's time, the big players have an incentive to create an echo-chamber for you, guaranteeing you have a higher probability of a positive experience when you use your X platform. A similar phenomena is present in cable news (MSNBC/CNN:neoliberal, Fox News:conservative), anyone watching will acknowledge the news they are watching IS SKEWED but will watch it regardless, despite the fact they'll admit it may be altered (thus less factual).

What will change is how the "channels" are created and maintained. Here is where Facebook has an ungodly level of power, it wouldn't be hard to divide the political spectrum into many more pieces than the traditional conservative and liberal lanes. The amount of possibilities are mind-boggling.