This will give you an indication of how many times a search is performed in a month (low numbers are not very useful unless there is a very clear buying signal in the keyphrase – working hard for five hits a month is not recommended in most cases) and how much the phrase is “worth” per click to advertisers (e.g., how much someone will pay to use that keyphrase). The more it’s worth, the more likely it is that the phrase is delivering business results for someone.
SEO is also about making your search engine result relevant to the user's search query so more people click the result when it is shown in search. In this process, snippets of text and meta data are optimized to ensure your snippet of information is appealing in the context of the search query to obtain a high CTR (click through rate) from search results.
Unfortunately, SEO is also a slow process. You can make “quick wins” in markets which are ill-established using SEO, but the truth is that the vast majority of useful keyphrases (including long-tail keyphrases) in competitive markets will already have been optimized for. It is likely to take a significant amount of time to get to a useful place in search results for these phrases. In some cases, it may take months or even years of concentrated effort to win the battle for highly competitive keyphrases.