- Speed: Static HTML pages are small, lightweight and perform blazingly fast. You'll notice the difference.
- Versioning: Contents and files remain on your computer. Perform backups or keep track of changes via GIT or SVN — it's quite easy without a database.
- Flexibility: Ruby and Liquid — Jekyll's foundation — empower you to easily extend its functionality. Or just use one of many plugins created by a striving community.
- Security: Anything you'll ever put on your server are static files — chances are good that you'll never need to worry about security concerns anymore.
If that still doesn't convince you to at least give it a try, I'd like to encourage you to head over to the Jekyll website and see it for yourself.
Heck, it's that good — I even wrote all of the guides for the theme documentation with it!