Before you dig into some of the more technical ways to improve SEO ranking, always remember that writing compelling, high-quality content that attracts interest and compels visitors to share it and link back to it is vital. Good content has the best chance of being viral content, and Google rewards content virality heavily in its rankings algorithm.
Click through rate: Except for high purchase intent searches, users will click on paid search listings at a lower rate than organic search listings. Organic listings have more credibility with search engine users. In one UK study, published by Econsultancy, only 6% of clicks were the result of paid listings. In another study, it was 10%. The important thing to remember is that click through rate varies by purchase intent. Organic rankings will get more click through rates for “top of funnel” keyword search queries.
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.[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. 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.