You've finally gotten your Drupal website to the point where you feel like it is ready to go, but during final testing it seems painfully slow. With page loading speed a factor in customer retention (as well as search engine rankings), you need your pages to load as swiftly as possible.

You've used CSS sprites every place you can so that the user only has to download a few images instead of a few dozen. You've got Drupal's core caching system turned on. You've got Drupal set to aggregate CSS and JavaScript files. You've even tweaked Views' caching settings. But you're still not where you want to be.

Your website needs the Boost module. Actually, nearly every Drupal website should really be running this module. It takes a little bit to set up, but it is definitely worth it (especially on shared hosting).

What the boost module does is eliminate the need for Apache to hit your MySQL database for every visit. It's a simple concept, really. For content that doesn't doesn't pertain to authenticated users and is an HTTP GET, Boost completely bypasses Drupal and MySQL.

Boost creates static copies of each page of your website and stores them in a cache folder on your webserver. When an anonymous user visits your website, the URL is aliased to the cached version of the page. These cached versions are built when you create or edit a node or when cron runs. This way, Drupal doesn't have to build the page upon request and the only thing that you've got left to do is image optimization.

So if your website is aimed toward anonymous users, install Boost and make their experience better.