From a (rather puzzled) NYT piece on Drudge:
A big part of the reason he is such an effective aggregator for both audiences and news sites is that he actually acts like one. Behemoth aggregators like Yahoo News and The Huffington Post have become more like fun houses that are easy to get into and tough to get out of. Most of the time, the summary of an article is all people want, and surfers don’t bother to click on the link. But on The Drudge Report, there is just a delicious but bare-bones headline, there for the clicking. It’s the opposite of sticky, which means his links actually kick up significant traffic for other sites.