What do you need the people that come to your page to see or do that PHP hosting can help with? That is a very long list as well. The shopping cart system, for one, is the biggest application that a lot of web masters use for the promoting of their business. The little bells and whistles, figuratively and literally, on your web pages can be generated by the appropriate imbedding of PHP scripts in your pages are all too familiar. While some may have a tendency to overdo these kinds of scripts, the ones that have everybody going to the bank with are the ones that allow you to accept payment from your customers by credit card. This does make it convenient for them to make their purchase in a safe, encrypted way.
Probably one of the biggest benefits that others see is the way that your page loads so much faster than others in your niche because of the scripting that does not get in the way of the web browser but actually helps it to load.