PPC (Pay-Per-Click): this refers to any online advertisement that is priced according to the number of times people click on the ad itself. This is the most popular and most common type of online advertising nowadays. In fact, this “PPC” model is the primary reason why digital advertising is considered more accountable and measurable than almost all other types of advertising. With PPC advertising, you can show your ad to hundreds of thousands of people for free, because you’re only charged for the clicks. If you buy a newspaper advertisement or a billboard ad, you are charged without regard to the number of people who take an action based on the ad itself.