Jan. 8, 2014 -- In "Google May Not Be Showing Your Desired Ad To Put More Money in Their Pocket" author Raymond Hackney leans heavily on an article published on the influential Search Engine People Blog in 2012 titled "The Google AdWords Trap: Chances Are You're Paying Too Much for Your Google AdWords Clicks" to explain what can happen when you have 4 keywords set to phrase match.
Which of your 4 keywords will be triggered?
The answer is any of them. [...]
Mitchell illustrated an example which makes the Search Engine People article very much worth reading.