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, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
If you mean that you want to advertise your product on the Internet and pay for the advertisement according to the number of clicks (on your advertisement) and the more the clicks, the more money you pay to the owners of the website, then there is nothing wrong with this, under the consideration that the contract here consists in Ji'aalah ( stipulated price for performing a service) for browsing, and whenever they bring browsers to the advertisement, they earn the price. However, they are obligated to abide by the terms and conditions of the contract, so they should not bring false visitors or hire visitors who do not have any interest in the product at all, as many companies do.
On the other hand, if the contract consists in you renting a space for the advertisement on the basis that the fee corresponds to the number of clicks, then the fee is undetermined as we have already clarified in Fatwa 98851.
Allaah Knows best.