Why not jsp?

Why Java Pro hosting in asp? (http://www.fawcette.com/javapro)
As I knew almost web sites are built by either asp or php, not jsp.
Do you know why?

PHP's extremely popular for a variety of technical reasons, including performance. ASP's popular because it's closely associated with Microsoft/IIS.

To add to what Michael stated, I also believe that PHP and ASP are more widespread because of ease of use. Face it, Java, which you need to know to effectively use JSP, is more difficult to learn than either one of those languages. I think that frightens many people away from it.
A large number of enterprise web applications seem to be using Java these days, but much of this is on intranets so it isn't always apparent. The banking industry seems to have gone towards Java in a big way for online banking however.