|7||How do I viralize a YouTube video and tip a Groupon deal?|
A quick recap of where we have been so far in the space of online services and web 2.0. In Chapter 3, we discussed the recommendation of webpages with an objective metric computed by Google from the graph of hyperlinked webpages. In Chapter 4, we discussed the recommendation of movies with subjective opinions estimated by Netflix from movie–user bipartite graphs.
Then we investigated the wisdom of crowds. In Chapter 5, we discussed aggregation of opinion in (more or less) independent ratings on Amazon. In Chapter 6, we discussed resolution of opinion conflicts in Wikipedia.
In this chapter, we will talk about dependence of opinions, taking a macroscopic, topology-agnostic approach, ...