Do you know that using a CDN to serve your static files improves your server's performance? This one runs on Nginx because it is much faster than apache2 for static files and uses less memory.
When I wrote an article that went viral on hackernews, accessing each page resulted in 20 additional web requests. Apache and PHP can easily handle 100 requests per second. However, 100 requests quickly turns to 2000 requests per second with the additional requests loaded by the article. Bots scanning the entire website also drain resources and that quickly crashed my server.
Whenever I write content on my blog I upload all the assets on a separate server. This includes images, JavaScript, any custom styling. This way, the blog engine and the server it runs on only has to worry about generating and serving the content. All additional files are served by this additional server that is optimized for static file serving.