Appendix A. Glossary
The percentage of users who exit from a given web page.
The average amount of time that visitors spend actually interacting with content on a web page, based on mouse moves, clicks, hovers, scrolls, and so on. Also known as engagement time.
A form of spyware perpetrated by unscrupulous advertisers, typically used to display alternate advertisements or pop-up ads.
A form of marketing where a website pays another website for sales that result from their customer referrals.
Ads placed within mobile or social applications.
The position achieved by a PPC ad, on average, on a search results page.