HTTP Compression is one of the best bang for the buck optimizations available in Microsoft's IIS webserver. HTTP compression works by compressing data before it's sent to the client. Images and executables are already heavily compressed, but much of a website's content is completely uncompressed. IIS can be setup to compress HTML, ASP, ASPX, JS, JSON, CSS, any other uncompressed content found on your web site.
Why Use HTTP Compression?