171. Engage › introduction to engageIn all of this, sometimes performance marketing or affiliate marketing is usedto drive traffic and engagement on a pay for performance basis. Many affiliateswill use any of the channels that we will be discussing, and as a marketer, youmay opt to use affiliates for marketing activities.While measurement and tracking will be discussed in each chapter, it’s worthgoing into the chapters with an understanding of how we track, report on andpay for various online campaigns.There are several terms you will see used throughout these chapters: • Impression: when an advert or a piece of online content is served (and hopefully seen by a web user). • Interaction: when a user interacts with an advert or content, such as playing a video, playing a game, or perhaps even leaving a comment. • Click: exactly what it sounds like, when a user clicks on a link or advert. This is different to an interaction, because when a user clicks, they go to a different page on the web. • Action: when a user completes a predetermined action, such as making a purchase, signing up to a newsletter or downloading some content.These terms then lend themselves to different ways of paying for and measuringonline campaigns. Sometimes we talk about campaigns in terms of cost perthousand (Mille) or CPM impressions. This is when campaigns are paid for interms of the number of times content was served. It’s used frequently in onlineadvertising, but is also a way of measuring social content.One can also look at the cost per interaction: the cost of a user interacting witha piece of content. Some of the most successful online campaigns are run ona cost per click (CPC) basis, where you don’t pay for content to be served, butrather for each click on that content. Lastly, payment or measurement can beregarded in terms of the cost per action (CPA): the cost of a user taking action.As you work through the following chapters, the above will be become clearerto you.Remember, the chapters that follow are important arrows in your digitalmarketing quiver. However, a strategic approach is required in order for youto determine the best solutions to meeting your online goals. You don’t needto tackle everything at once: focus on the foundations first, and then track andmeasure in order to determine which channels are working best. 167