Basically, SEO keyword research should be an ongoing and ever-evolving part of your job as a marketer. Old keywords need to be reevaluated periodically, and high-volume, competitive keywords (or “head” keywords, as opposed to long-tailed keywords) can often be usefully replaced or augmented with longer, more specific phrases designed not to bring in just any visitor but exactly the right visitors. (Who visits your site – particularly if they’re people who are actively looking for your services – is at least as important as how many people visit.)
Consider the age of your business. If you just opened your business and launched your website, it’s going to take time to develop your SEO and begin to appear organically in the search. While that doesn’t mean you shouldn’t put together an SEO strategy, it does mean that you could benefit from an SEM strategy until you build your SEO. SEM is an effective way to drive traffic while building organic SEO.
While SEO allows you to optimize your website for a greater chance in appearing higher in search results, and online advertising allows you to send promotional content to the target audience of your choosing, SEM combines both benefits as your content is both optimized for higher search rankings and is placed primarily in front of audiences who are most likely to convert when they click on your ads.