It is amazing how we think about least significant things and put in Maximum effort rather than take care of low hanging fruits first. GZIP RFC came out around 1996 and all modern browsers (HTTP/1.1 supported Browsers) support GZIP and still it is amazing how many website doesn't support such a basic trick to save 50% of their bandwidth costs. Just adding GZIP support reduces bandwidth by 50% (70% if the website is Mostly Text) resulting in huge amount of savings.
How to Enable GZIP for Apache:
1) Make sure LoadModule deflate_module modules/mod_deflate.so in your httpd.conf
2) Add the following lines to httpd.conf
SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png|rar|zip|pdf)$ no-gzip dont-vary
Header append Vary User-Agent
and you are done. The configuration is telling Apache to GZIP every content except for Images, Zipped content and PDF files which are already in compresses format.
Next time when a browser sends request with HTTP Header:
Accept-Encoding: gzip, deflate
You webserver serves content in GZIP format and notifies the same with a proper reponse Header:
Enable GZIP on your servers today and save the Earth.