As the number of sites on the Web increased in the mid-to-late 1990s, search engines started appearing to help people find information quickly. Search engines developed business models to finance their services, such as pay per click programs offered by Open Text[7] in 1996 and then[8] in 1998. later changed its name[9] to Overture in 2001, was purchased by Yahoo! in 2003, and now offers paid search opportunities for advertisers through Yahoo! Search Marketing. Google also began to offer advertisements on search results pages in 2000 through the Google AdWords program. By 2007, pay-per-click programs proved to be primary moneymakers[10] for search engines. In a market dominated by Google, in 2009 Yahoo! and Microsoft announced the intention to forge an alliance. The Yahoo! & Microsoft Search Alliance eventually received approval from regulators in the US and Europe in February 2010.[11]
We still seem to have PageRank as an important ranking factor from Google, but have been told that Google is using a machine learning approach called RankBrain. The focus of this RankBrain approach is to help the search engine understand the meaning of queries better, and provide answers that (still) focus upon meeting the situational and informational needs of searchers.

Display advertising - As the term infers, Online Display Advertisement deals with showcasing promotional messages or ideas to the consumer on the internet. This includes a wide range of advertisements like advertising blogs, networks, interstitial ads, contextual data, ads on the search engines, classified or dynamic advertisement etc. The method can target specific audience tuning in from different types of locals to view a particular advertisement, the variations can be found as the most productive element of this method.