As competition in the UK internet market increases, search engine marketing (SEM) has emerged as an essential strategy for businesses. Search engine marketing (SEM) allows businesses to pay for their ads to appear at the top of search engine results, making it easier for customers to find them. Increasing website traffic in a short period of time is a powerful method, with some companies reporting an increase in site visits of up to 200 percent as a result of their search engine marketing efforts. What are the key differences between search engine marketing (SEM) and search engine optimisation (SEO), and how can firms develop an effective SEM strategy?