Jessica Knobbe

The Wikipedia definition of search engine marketing is as follows:  

Search engine marketing, or SEM, is a form of Internet marketing that seeks to promote websites by increasing their visibility in search engine result pages (SERPs) through the use of paid placement, contextual advertising, and paid inclusion.

You can also think of it as the variety of methods used to deliver your website or ad to based on a search query.  Think of how powerful that is.  People are looking for specific goods or services based on targeted keyword queries.  Show them relevent information and content you are already light years ahead of the curve and in the first stages of the sales funnel.  Instead of treating your ad as something disruptive to their experience they are ready for engagement and purchase.

Make sure that you are optimizing for the right keywords and phrases.  Make sure your content is relevent to what you are optimizing for.  Know your target audience and how they will search for your product.  Just because someone in the industry refers to it as a Whatchacallit, your audience might know it more commonly as a Whoozerwhatzle.   Are you optimizing for Whoozerwhatzle?  Because if you are not, someone else probably is.