According to Theo Röhle of the University Hamburg (Germany) the commercial exploitation of advertising space has become the main task of search engine companies. In ‘Think of it first as an advertising system’: Personalisierte Online-Suche als Datenlieferaant des Marketings” (pdf) he analyses the elicitation of user data of search engines with a focus on personalized search.
Personalized online search as offered by Google and Yahoo can indeed help to improve search results and increase their relevance for the individual user. But what makes these services interesting to search engine companies is the protocoling and interpretation of user behavior and the profiling of its users. Thus collected user data can be used for commercial interests, possibly without time limits.
As listed companies search engine firms are depending on investors and financial markets. Therefore it is indeed their strong interest to maximize profits. Google is a (close-to) monopoly in the search engine market. Investors need companies that grow steadily. It is hard for a company like Google to grow in the search engine market, which it controls in big parts. However Google can grow "in depth", meaning it can grow by collecting more information and utilizing it commercially.
Also Theo Röhle comes to the conclusion, that user data and information that was firstly ascertained to improve search engine results will be, because of the "commercial pressure to be exploited", utilized. This information is indeed the capital of search engine companies.
The question hence: Do I, as a user, want to participate in this process of capitalization of my personal data? And: What alternatives would there be?
In regards to the findings of Theo Rhöle search engines based on Free Software and Free Algorithms become a vital interest of every Internet user, who wants to protect his/her private data and continue using modern Internet services. Only Free search engines based on Free layers can avoid monopolistic structures, where one commercial party (nearly) controls the flow of information, public as well as private.