The direct mail is the marketing channel that has the most expensive CPM.
What is the CPM?
The CPM is the acronym of the term Cost per thousand. This is used in marketing to show the cost of 1000 advertisements on a web page.
The advertisers that use this have to pay each time that their adverts come up. Publishers earn income anytime such ads come up on their page.
Read more on cpm here:
https://brainly.com/question/24860817
