The document discusses how Google's biggest search competitor is no longer other search engines like Bing or Yahoo, but instead niche search competitors like Amazon, YouTube, Yelp, Pinterest, Zillow, and Quora that have become the go-to search tools for specific categories like online shopping, videos, local businesses, home decor, real estate, and questions/answers. It argues that SEO specialists need to expand their definition of search engine optimization to include ranking well in these niche search engines in order to provide the best guidance to businesses.