For as long as we can remember, search engine dominance has always looked the same; Google on top, with Bing and Yahoo clambering to get their piece of the pie. We all agree that Google has solidified itself as the king of search engines. Recent history shows that Bing has grown steadily over the last few years to eventually grab 20 percent of the market share (compared to Google's 66 percent). An interesting development no one saw coming was the deal between Bing (Microsoft) and Yahoo to have Bing lend it's search engine to Yahoo. Since then, all Yahoo search results have come from Bings' algorithms. It may look like Yahoo has it's own search engine, but the brains behind Yahoo Search Results is Bing. Surprise, Yahoo reached an agreement with Google, creating a partnership between these previous market competitors that could help shape the future of search as we know it. "In October, the Company reached an agreement with Google that provides Yahoo with additional flexibility to choose among suppliers of search results and ads. Google's offerings complement the search services provided by Microsoft, which remains a strong partner, as well as Yahoo's own search technologies and ad products." - Yahoo Investor Relations What's in the deal? The possibility of a Google-Yahoo deal was made possible when the terms of Yahoo's deal with Bing was renegotiated that now gives Yahoo the right to to seek search ad provisions from other companies (ie. Google). Prior to this, they were locked into using Bing exclusively. This new deal secured by Yahoo will allow Google to provide search results and ads to Yahoo. In return, Google will pay Yahoo a percentage of all revenue generated from display ads. This new freedom could allow Yahoo to leverage both Google and Bing search engines as they see fit. Bing is no light weight. They have worked hard to develop advanced search algorithms and features to rival Google, but it's been a challenge for them to catch up to a competitor that's dominated and earned authority the way Google has. With that said, Yahoo now has the option to take advantage of Google or Bing technology to provide the best user experience when serving their search results (and of course revenue generating ads). How will this affect SEO? You'll be happy to know that your job will not change that much. Ranking factors will remain very close to what we know now. You will still do the same keyword research, on-page optimization and off-page optimization such as link building and social signals. What will change is the days of only using Google SERP rankings as our measure of growth and success. You will soon have to keep an close eye on how your sites perform on multiple search engines. Your incoming search queries will be coming from a variety of sources. What about Paid Advertising? Very soon your Google paid ads could be showing up in Yahoo SERP pages. You have to start thinking about: How are the user base demographics on Yahoo different from Google? Could this affect how I construct my ads? Will this affect the cost of advertising? ... What have we learned? You can't blame Yahoo... If you can't beat'em Google, join'em!