By Guy Stannard Search engine marketing, also known as SEM, is a continual effort on the part of businesses to gain more online attention from their targeted markets. It helps them to secure ads on top of the results that search engines produce. Even if the sites that these companies maintain do not rank well, people will still have access to their links. You can find out more about these processes by working with a Dallas TX SEO firm. People who use the Web know the difference between listings that are organic and those that are not. If they...