Already knew that Google Adsense has 3 different type, that is:

1. Google Adsense for Content

This ads targeting our blog or site readers. We hope that our readers click our ads after / before reading our updated article/posting

2. Google Adsense for Adword

This the same as above but it is more specific to Word

3. Referral Program

This is favourite type, we can earn a lot of money from this type of Google Adsense. This is work by uploading the picture from referral site, such as Google itself or from Firefox.

Just add one or all of them to your web/blog and start making money with them :)