Many ISPs use proxy servers to help speed up Internet access for their customers. The idea is that these servers keep a copy of your page on the proxy server (for a certain amount of time), and update their copy as you change your page. The effect of this is that while your page may have only be downloaded from your server once, it may have been seen by a number of peo¬ple.

If you have static pages that rarely change, then caching can go some way to reducing your hosting bill. Clever use of meta tags can tell the browser not to bother reloading the page from the server if it is available on the users computer or a proxy server. Since these revisited pages do not have to be reloaded from your server, a single page re¬quest in your logs could equate to several-hundred page views for that page (particularly if you were paid a visit from a large proxy server used by some of the bigger ISPs).



Dynamic pages are not so suited to caching, but if the dy¬namic elements of pages are not visitor or time sensitive, then caching can be used to some degree to keep that data transfer bill down; for example, a page using the date may only need to be built by the server once each day. In the case of building dy¬namic pages, caching can also be used to reduce the server load by storing results of database queries in the server cache.