There are many reasons explaining why advertisers choose the SEM strategy. First, creating a SEM account is easy and can build traffic quickly based on the degree of competition. The shopper who uses the search engine to find information tends to trust and focus on the links showed in the results pages. However, a large number of online sellers do not buy search engine optimization to obtain higher ranking lists of search results, but prefer paid links. A growing number of online publishers are allowing search engines such as Google to crawl content on their pages and place relevant ads on it. From an online seller's point of view, this is an extension of the payment settlement and an additional incentive to invest in paid advertising projects. Therefore, it is virtually impossible for advertisers with limited budgets to maintain the highest rankings in the increasingly competitive search market.
Optimizing a website may involve editing its content, adding content, modifying HTML, and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic. By May 2015, mobile search had surpassed desktop search.