In this type of model, both publisher and advertiser agree to a fixed amount that will be paid for each click. Most time, the publisher has a rate card for PPC plans based on different areas of their website or network. The amount varies as per the content that generally attracts more or fewer people.
Bid based PPC :
In this type of model, the advertiser competes with other advertisers in a private auction hosted by a publisher. The advertiser will inform the publisher of the maximum amount of bid he is willing to pay.