Going back to our online shoe store example, it would be great to rank #1 for the keyword "shoes" ... or would it?
It's wonderful to deal with keywords that have 5,000 searches a day, or even 500 searches a day, but in reality, these popular search terms actually make up less than 30% of the searches performed on the web. The remaining 70% lie in what's called the "long tail" of search. The long tail contains hundreds of millions of unique searches that might be conducted a few times in any given day, but, when taken together, comprise the majority of the world's search volume.
Another lesson search marketers have learned is that long tail keywords often convert better, because they catch people later in the buying/conversion cycle. A person searching for "shoes" is probably browsing, and not ready to buy. On the other hand, someone searching for "best price on Air Jordan size 12" practically has their wallet out!
Understanding the search demand curve is critical. To the right we've included a sample keyword demand curve, illustrating the small number of queries sending larger amounts of traffic alongside the volume of less-searched terms and phrases that bring the bulk of our search referrals.
Where do we get all of this knowledge about keyword demand and keyword referrals? From research sources like these:
Google's Ad Words Keyword Planner tool is a common starting point for SEO keyword research. It not only suggests keywords and provides estimated search volume, but also predicts the cost of running paid campaigns for these terms. To determine volume for a particular keyword, be sure to set the Match Type to [Exact] and look under Local Monthly Searches. Remember that these represent total searches. Depending on your ranking and click-through rate, the actual number of visitors you achieve for these keywords will usually be much lower.
Other sources for keyword information exist, as do tools with more advanced data. The Moz blog category on Keyword Research is an excellent place to start.
In order to know which keywords to target, it's essential to not only understand the demand for a given term or phrase, but also the work required to achieve high rankings. If big brands take the top 10 results and you're just starting out on the web, the uphill battle for rankings can take years of effort. This is why it's essential to understand keyword difficulty.