What is Search Engine Optimization?
Due to the increasing digitization and the growing importance of the Internet as a sales channel, the digital presence on the World Wide Web is now an indispensable marketing tool for the majority of companies. If you want to reach the highest possible number of (potential) customers on the Internet, it is no longer sufficient to be present “only” with a website or an online shop in the hope you will be found by chance or through personal recommendations.
Although many service providers and platforms, especially Google, offer paid advertising on their websites. However, investing in such advertising can become very expensive in the long run. If companies focus on the presence in the organic, unpaid results of the search engines, they will find high competition in almost all industries, when it comes to the first spots in the search results.
Today, search engines like Google are among the most critical applications on the Internet. On the one hand, they are indispensable tools for finding their way through the faster-growing flood of data on the World Wide Web, and on the other, they are substantial economic powers. 
Internet users use search engines such as Google, Bing or Yahoo!, to find products and services in the flood of data on the World Wide Web. The users of search engines paying maximum attention to the first ten search results from page 1. The search results that are not displayed on the first results page are, in the eyes of the searchers, non-existent in the majority of cases. This fact is also reflected in studies that had the use of search engines on the subject. You can find more information about this topic, for example in: “User Behavior Study” by iProspect. According to iProspects findings, only 62% of all search engine users examine the complete search hits of the first results page. Only 10% of users looked at the first three results pages.  Also, an eye-tracking study carried out by Did-it, Enquiro, and Eyetools revealed that the first 3 places of the organic search results are read by 100% of the users, while 10th places are only read by 10% of the perceived ones.  These and other studies suggest that it makes sense in all respects to be displayed with the relevant keywords on the top 10 positions of the search engines.
Based on these findings, a whole branch of industry has developed in the last ten years, which offers optimizations for websites and online shops, so that they are displayed as prominently as possible in the hit lists of search engines. In the meantime, there is a multitude of more or less scientific literature on the subject as well as numerous internet blogs and communities in which there is a lively exchange about the latest developments in the field of search engine optimization. Besides, there are more and more agencies and freelancers offering professional SEO consulting as a service.
 Vgl.: Alby/Karzaunikat, 2007, S. 1  Vgl.: iPprospect, 2006, S. 3 Vgl.: http://www.prweb.com