1. A spam detection system, comprising: a classifier training component that receives a first set of training pages labeled as normal pages and a second set of training pages labeled as spam pages, wherein the classifier training component trains a web page classifier based on both the first set of training pages and the second set of training pages; and a spam detector that receives unlabeled web pages and, utilizing a computer processor, applies the web page classifier so as to classify the unlabeled web pages as either spam pages or normal pages.