This chapter addresses measurements of digital editorial units and clutter levels. The online and digital media context presents new challenges because the passive and captive environment of traditional offline media is replaced by the active and self-paced environments in digital media. The competition for users' attention online is fierce, as users can easily move to another web page at the click of a mouse or the touch of a finger in mobile media. One fundamental issue challenging advertisers is that some consumers have an overall negative attitude toward advertising in general due to its profit-making persuasion motive and its negative effect on society. Advertising is seen by some to lower the quality of content and sacrifice the independent nature of the news media. There are three types of clutter effects on audiences: cognitive, affective, and behavioral. The most common measures of the effects of clutter are its negative cognitive effect on memory of advertisements.