Usability And User Experience are posing a major threat to the SEO industry. This fact came to the fore after seeing the recent trend of ranking the pages by Google. Google from beginning have given most importance to user experience and usability.
Gone are the days when keyword density and PageRank were the major criteria for ranking the pages. In 2006 there has been a sea change in the user testing methods of Google. They have employed Quality Raters, Quality Evaluators, and Usability Researchers this year. Human role has gained lot of prominence in Google for evaluating search results. Their recent AdWords blog talks about assessing AdWords landing pages quality for giving better experience to their users. Google is very particular about the pages in the search results should satisfy the needs of the users. Their methods of ranking pages is centered around needs and intentions of the users. The pages which are inappropriate for the keyword and the pages which have lot of ads and affiliate links are ranked low. Pages will also get negative ranks if it uses META descriptions or wrong TITLE text and hide keywords.
This trend means that SEO practice is becoming more user centric while the tech tricks are becoming things of past now in fact on the verge of extinction. Since Google is the leader in the search marketplace, its competitors might follow the suit soon.