A combined approach of deductive and inductive reasoning can leverage the clear separation between the evolving (streaming) and static parts of online knowledge at conceptual and technological levels. What are the hottest topics discussed on Twitter? Which topics have my close friends discussed in the last hour? Which movie is my friend most likely to watch next? Which Tuscan red wine should I recommend? With many popular social networks publishing microblogs and feeds, the information required to answer these queries is becoming available on the Web.