Search engine optimization (SEO) is the process of improving the visibility of a website or webpage on a search engine results page (SERP) so as to make a company’s website more discoverable (i.e., on the first page/s), thereby driving traffic and sales. Tedious, involving technical and business decisions, and not guaranteeing results—it nonetheless provides lasting benefits.
SEO often involves the concerted effort of multiple departments within an organization, including the design, marketing, and content production teams. While some SEO work entails business analysis (e.g., comparing one’s content with competitors’), a sizeable part depends on the ranking algorithms of various search engines, which may change with time. Nevertheless, a rule of thumb is that websites and webpages with higher-quality content, more external referral links, and more user engagement will rank higher on a SERP.
Search engine optimization is a key part of online marketing because search is one of the primary ways that users navigate the web. In 2014, over 2.5 trillion searches were conducted worldwide across search engines such as Google, Bing, Yahoo, Baidu, and Yandex. For most websites, traffic that comes from search engines (known as "natural" or "organic" traffic) accounts for a large portion of their total traffic.
Search results are presented in an ordered list, and the higher up on that list a site can get, the more traffic the site will tend to receive. For example, for a typical search query, the number one result will receive 40-60% of the total traffic for that query, with the number two and three results receiving significantly less traffic. Only 2-3% of searchers click beyond the first page of search results. Thus, even a small improvement in search engine rankings can result in a website receiving more traffic and potentially business.
Because of this, many businesses and website owners will try to manipulate the search results so that their site shows up higher on the search results page (SERP) than their competitors. This is where SEO comes in.
The SEO process targets mostly organic links and search engine result placement; still, it is often complemented by more aggressive measures (e.g., paid search ads) and is often part of traditional marketing campaigns.