Cost per mille requires only that the publisher make the advertising available on his or her website and display it to the page visitors in order to receive a commission. Pay per click requires one additional step in the conversion process to generate revenue for the publisher: A visitor must not only be made aware of the advertisement but must also click on the advertisement to visit the advertiser's website.
In corporate law and taxes, an affiliate is a company that is related to another company, usually by being in the position of a member or a subordinate role, a subsidiary. According to Investopedia, a subsidiary is a company "whose parent is a majority shareholder." (That means the parent owns 51 percent or more of the other company's shares of stock.