On April 24, 2012 many started to see that Google has started to penalize companies that are buying links for the purpose of passing off the rank. The Google Update was called Penguin. Since then, there have been several different Penguin/Panda updates rolled out by Google. SEM has, however, nothing to do with link buying and focuses on organic SEO and PPC management. As of October 20, 2014 Google has released three official revisions of their Penguin Update.
In the parlance of digital marketing, advertisers are commonly referred to as sources, while members of the targeted ads are commonly called receivers. Sources frequently target highly specific, well-defined receivers. For example, after extending the late-night hours of many of its locations, McDonald's needed to get the word out. It targeted shift workers and travelers with digital ads, because the company knew that these people made up a large segment of its late night business. McDonald's encouraged them to download a new Restaurant Finder app, targeting them with ads placed at ATMs and gas stations, as well as on websites that it new its customers frequented at night.