When it comes to search engine marketing, there may be no larger misnomer, no more archaic term than the ubiquitous keyword. In my view, there should be an official migration to the more accurate term keyphrase, but for now I will be forced to use what I consider to be an inaccurate term. My frustration with this term is that it quite simply implies a single word, which is rarely the strategy that we employ when doing keyword research and selection in the service of PPC and SEO campaigns.
All too often, people dramatically overthink the most basic keyword research concepts; keyword generation should start simply with answering the question of “What products or services do you sell?” If you sell dog food online, the root words dog and food alone would be very poor keywords because on their own, neither dog nor food do a remotely good job at describing what you sell. Though this example makes it obvious, many times we have to fight through our urge to include those bigger, broader root keywords.
Jim Forbes-IMC 619 