Why are META tags important?

From Wikipedia:
Meta tags have been the focus of a field of marketing research known as search engine optimization or SEO. In the mid to late 1990s, search engines were reliant on Meta tag data to correctly classify a web page. Webmasters quickly learned the commercial significance of having the right Meta tag, as it frequently led to a high ranking in the search engines - and thus, high traffic to the web site.

As search engine traffic achieved greater significance in online marketing plans, consultants were brought in who were well versed in how search engines perceive a web site. These consultants used a variety of techniques (legitimate and otherwise) to improve ranking for their clients. You can see any web site's Meta tags by viewing the source code.

The two most popular Meta tags used for search engine optimization is the Meta description tag and Meta keyword tag. The Meta description tag allows web site owners to describe what the web page is about. Search engines such as Google still use this to display the description of a web site in the search results. The Meta keyword tag allows site owners to put keywords in it to help search engines decide what a web site is about.

In the early 2000s, search engines veered away from reliance on Meta tags, as many web sites used inappropriate keywords or were keyword stuffing to obtain any and all traffic possible.

Some search engines, however, still take Meta tags into some consideration when delivering results. In recent years, search engines have become smarter, penalizing web sites that are cheating (by repeating the same keyword several times to get a boost in the search ranking). Instead of going up in the ranking, these sites will go down in ranking or on some search engines, will be kicked out of the search engine completely.

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