Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using metadata to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.[10][dubious – discuss] Web content providers also manipulated some attributes within the HTML source of a page in an attempt to rank well in search engines.[11] By 1997, search engine designers recognized that webmasters were making efforts to rank well in their search engine, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms to prevent webmasters from manipulating rankings.[12]

In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[21] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.

Every one of those engagements can amplify a post tenfold depending on the size of their network. And really you’re educating them on, ‘Hey, when you engage with our content,  you’re not only just liking the content, but you’re opening that content up to all of your network, which can ultimately help with building the business’ bottom line, getting more awareness, which in turn drives more leads, and helps move people down the funnel, they build trust when they see your name more often.’
It’s an investment. Whether you have a trusted Internet marketing company handle your SEO activities or you travel the journey solo, you are making a solid investment in your website. Every time you optimize a landing page or write a blog post, you’re introducing new and relevant content to your website. Search engines love recent, relevant content.
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 Goto.com[8] in 1998. Goto.com 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]
Search engine marketing is the practice of marketing a business using paid advertisements that appear on search engine results pages (or SERPs). Advertisers bid on keywords that users of services such as Google and Bing might enter when looking for certain products or services, which gives the advertiser the opportunity for their ads to appear alongside results for those search queries.

Search engine marketing’s greatest strength is that it offers advertisers the opportunity to put their ads in front of motivated customers who are ready to buy at the precise moment they’re ready to make a purchase. No other advertising medium can do this, which is why search engine marketing is so effective and such an amazingly powerful way to grow your business.
Page and Brin founded Google in 1998.[22] Google attracted a loyal following among the growing number of Internet users, who liked its simple design.[23] Off-page factors (such as PageRank and hyperlink analysis) were considered as well as on-page factors (such as keyword frequency, meta tags, headings, links and site structure) to enable Google to avoid the kind of manipulation seen in search engines that only considered on-page factors for their rankings. Although PageRank was more difficult to game, webmasters had already developed link building tools and schemes to influence the Inktomi search engine, and these methods proved similarly applicable to gaming PageRank. Many sites focused on exchanging, buying, and selling links, often on a massive scale. Some of these schemes, or link farms, involved the creation of thousands of sites for the sole purpose of link spamming.[24]

This means that each organic search visit is worth $7.35. Chances are, you’ll spend WAY less than that to generate that one visit. How’s that for some rock-solid ROI? You can get even more specific with this by looking at the organic search traffic for a particular keyword. By extension, you can calculate the ROI of that keyword. You can begin to see how this can ramp up your SEO game.
Organic is what people are looking for; the rest of these simply put things in front of people who may or may not be seeking what you offer. We know that approximately X number of people are looking for Y every day. So if we can get on front of those people, we have a much greater opportunity to create long-term relationships and increase our overall ROI.