All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If the situation is as you have stated, (i.e. the users do not pay any fees), then it is permissible to take a commission from this company in return for advertising for it on your website, with the condition that the dealings and transactions of the company that you are advertising for are Islamically permissible. But it is not permissible for you to click on the ads of this company pretending that you are a new visitor because this is cheating and deceiving and eating people's money without right. The Prophet said: "Whoever cheats is not one of us." [Muslim] Moreover, Allaah says (what means): {And do not consume one another’s wealth unjustly.} [Quran 2:188]
Allaah Knows best.