SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors.[60] Search engines can change their algorithms, impacting a website's placement, possibly resulting in a serious loss of traffic. According to Google's CEO, Eric Schmidt, in 2010, Google made over 500 algorithm changes – almost 1.5 per day.[61] It is considered wise business practice for website operators to liberate themselves from dependence on search engine traffic.[62] In addition to accessibility in terms of web crawlers (addressed above), user web accessibility has become increasingly important for SEO.

I would like to talk about a case study for a large start up I worked on for over eight months in the Australian and US market. This client originally came to the company with the typical link building and SEO problems. They had been using a SEO company that had an extensive link network and was using less than impressive SEO tactics and methodologies over the last 12 months. The company was also losing considerable revenue as a direct result of this low quality SEO work. So, I had to scramble and develop a revival strategy for this client.
At our agency, we work with sites of varying sizes, from very large to quite small, and recently, we have noticed a trend at the enterprise level. These sites aren’t relying as much on Google for traffic any more. Not only are they not relying on Google traffic, but also, the sites are getting less than 10 percent (or slightly more) of their organic traffic from the search giant.