From all the company you can make most of money only at google.com/adsense. In order to earn from adsense you just need a
blog or website. After that register with Adsense . But
remember registering with Adsense is not as easy as you think, after few rejection you can take success there .
But one time if you permitted by google adsense then you can earn huge money from google.com/adsense by showing their advertisements , but one thing you have to remember is that clicking on their own Ads is totally prohibited by google . If any one caught then google will not be responsible for account termination