Modifiers in search engine phrases are used for two main reasons: to increase the percentage of ideal prospects in the traffic the phrase attracts, and to find terms that are easier to target on search engines. Adding the right type of modifiers to your search engine keyphrases will increase your chances of success.
Search Engine Guide’s Scott Buresh Looks into Search Engine Keyphrases and the Power of the Modifier:
Most search engine optimization experts agree that the keyphrase selection process is the single most important step in a search engine optimization campaign. However, clients frequently ask their search engine optimization company to target very general and competitive search engine keyphrases. While targeting such terms is usually not worth the effort, the addition of a simple modifier can take an ultra-competitive, general keyphrase and transform it into something useful- a phrase that attracts a large percentage of people that are looking for exactly what you offer, and for which high rankings are attainable.
In related news, Google’s December upgrade put more of a focus on these modifications and stemming. Stemming is the most significant change searchers should be aware of. When you now search on Google, it will automatically look up variations of words. So a search for “blog search” behind the scenes is looking for pages that have all of these words, and perhaps others, on them: