IN THIS CHAPTER
Understanding why the revolution in recommending products is important
Obtaining rating data
Using SVD when working with products and movies
One of the oldest and most common sales techniques is to recommend something to a customer based on what you know about the customer’s needs and wants. If people buy one product, they might buy another associated product if given a good reason to do so. They may not even have thought about the need for the second product until the salesperson recommends it, yet they really do need to have it in order to use the primary product. For this reason alone, most people actually like to get recommendations. Given that web pages now serve as a salesperson in many cases, recommender systems are a necessary part of any serious sales effort on the web. This chapter helps you better understand the significance of the recommender revolution in all sorts of venues.
Recommender systems serve all sorts of other needs. For example, you might see an interesting movie title, read the synopsis, and still not know whether you’re likely to find it a good movie. Watching the trailer might prove equally fruitless. Only after you see the reviews provided by others do you feel you have enough information to make a good decision. You also find methods for obtaining and using rating data in this chapter.
Gathering, organizing, and ranking such information is hard, though, and information overflow is the bane ...