The advantages of SEO

1. Research has shown that some people do not click on sponsored listings while others do not know that the links are paid for. About 80% of clicks occur on natural listings. This means that using search engine optimization is preferable to paid services because it is free.
2. A benefit of search engine optimization is its cost-effectiveness. There are no payments to search engines for being ranked or listed. This is good when compared to similar results gotten from paid services.
3. The general cost of search engine optimization is fixed and independent of the click volume. Removing initial costs, the cost per-click for the webpage or website owner decreases compared to a paid search, which has a variable cost depending on the number of clicks.
4. There are no costs for the addition or use of media.

The disadvantages of SEO
1. A problem with search engine optimization is the billions of webpages or sites in search engine indexes. Your webpages pan in the search engine depends on an ever-changing algorithm that is not published. Increasing the visibility of your site depends on your technical ability to guess the algorithm and to react quickly to changes.
2. Therefore, another disadvantage of search engine optimization is a lack of control.
3. Another issue is the use of black hat (unethical) SEO. These are search engine optimization methods are deceptive and if competitors use methods like that, your site may not rank as high as it could or should.
4. In very competitive categories, being listed in the first couple of results for competitive phrases is difficult and in cases like that, using pay-per-click services is advisable.
5. The use of search engine optimization can lead to excessive repetitiveness in an effort to designate a keyword or phrase. This will lead to the page or website being classifies as spam and the search engine will not rank it.
6. It can sometimes be easy to engage in unethical search engine optimization without realizing it. The consequences of black hat SEO, depending on the degree of use, range from a fine to being banned.

With a list of pros and cons like this, it can be quite difficult to make a case entirely supporting or discouraging the use of search engine optimization.
That being said, it is crucial to remember that SEO is a long-term strategy that more often than not, if done right, will produce good results.