The digital web magazine has a compelling paper about how "Content Aggregators Change Navigation and Control of Content". They present a "distributed navigation view" opposed to the previous "on-site navigation view" (“home page as the starting point” paradigm):

users navigate completely outside the site containing the target content. The only page they see is the one that the aggregator links to. So the IA that ends up getting users to the target content page isn’t the one on the site they end up on, it’s the aggregator’s site’s IA