I've just been reading a post on A Very Public Sociologist's blog and his tips for building an audience. He makes some interesting observations.
For my part I find that writing a title implying the presence of porn or references to Britney Spears with no clothes on drives an audience very successfully. But whether they come back again is another matter of course.
Interestingly many of the people searching for such items come from parts of the world that tend to take a dim view of such things. There's one for sociologists and indeed psychologists to ponder.
You can read the much more sensible tips of someone with a bigger, although not that much bigger audience than me via this link: A Very Public Sociologist: Building a Blog Audience