We get so focused on Google that it's easy to forget there are alternatives to Google search.\u00a0 Granted, the alternatives\u00a0 are not nearly as popular.\u00a0 At 66% market share and 11.7 billion searches during the month of February 2012 alone, Google clearly is the leader.\u00a0 But other search engines are worth understanding -- both from the perspective of when you are a searcher for information, and from the perspective of a site owner knowing that visitors may come from those other search engines. And just in case you are tempted to think 'hey, a search engine is a search engine - how different could they be?' let's take a deeper dive. According to Comscore, the top 5 search engines according to volume of search and market share are:\u00a0 Google, Microsoft, Yahoo, Ask and AOL. \u00a0However, when you look underneath the hood, there are really just two big players: \u00a0Microsoft's Bing and Google -- and a few smaller players. \u00a0Let's break them down further: Google We all know the Google search engine, right? \u00a0But did you know that Google actually has many search engines? For instance there's a Google search engine just for books. \u00a0There's an image search engine that lets you put in the URL of the image or upload one from your computer, and find the same image across the Web (if you're a photographer concerned about people ripping off your images, the image search engine may become your next best friend). \u00a0There's a full-text U.S. patent search. For site owners, Google offers a Webmaster Tools dashboard to help you keep tabs on any problems with your site in the Google index. \u00a0For instance, it can tell you if malware has been detected. \u00a0And don't forget to check out Google's \u00a0Search Engine Optimization Starter Guide (PDF) so you can make the most of traffic from Google to your site. Matt Cutts is the head of the Google Web spam team and he regularly gives information to the community about Google's search practices. \u00a0In many ways he is the public face of Google's search outreach. \u00a0His videos are particularly useful and for the most part understandable by small business owners. \u00a0You can find them at the Google Webmaster channel on YouTube. Bing Bing, a search engine from Microsoft, is the largest and most well established after Google.\u00a0 Yahoo, the original search giant from the 1990s, is also "powered by Bing" search results as of 2011.\u00a0 (Therefore, for our purposes, Yahoo will be lumped in with Bing.)\u00a0 According to Comscore, Bing and Yahoo together accounted for 5.1 Billion searches in February 2012 -- or 29% of the market.\u00a0 Bing has been growing steadily over the past few years. Bing emphasizes that it provides answers, not search results.\u00a0 Many people may find the distinction difficult to grasp, however. Bing.com has a stunning visual interface (a great big background image that changes daily greets you on the home page -- it's interactive, too): Like Google, Bing offers a Webmaster Toolbox that gives valuable information about your website, including crawl errors. \u00a0There's also a Bing Webmaster Center blog written by Duane Forrester, a Bing Senior Product Manager, that's pretty understandable and useful for small business owners and managers. \u00a0There's also this Getting Started checklist. Ask Ask.com includes a search engine and also has a human-powered question and answer feature.\u00a0 A couple of years ago Ask.com stopped investing in its own search technology, and although it's a bit of mystery whose search results Ask uses, most observers say Google.\u00a0 Since then Ask has been declining -- albeit very slowly -- in market share.\u00a0 It's now at about 3% market share, with roughly half a billion searches each month. AOL AOL's search constitutes a little over 1.5% of the market.\u00a0 It appears to be using Google's search technology.\u00a0 So once again, we're back to Google. Thus, as you can see, Google and Bing together make up most of the market share. \u00a0So, what are the others? \u00a0All are relatively small (but Google once was small, too).\u00a0 Let's take a look at a few of them: Duck Duck Go Duck Duck Go\u00a0is a\u00a0startup search engine is competing by leveraging the public's recent concern over Google's privacy policies.\u00a0\u00a0 According to Fred Wilson, a principal of Union Square Ventures, a venture capital backer of Duck Duck Go, other vendors should do the same, saying \u201cWe should encourage web and mobile services to lead with their privacy practices and let users vote with their feet. This is an opportunity for new web services who can use privacy as a basis for competition as Duck Duck Go does.\u201d\u00a0 Duck Duck Go says it does not collect or share browsing history, and it articulates understandable privacy policies, including one that is illustrated and starts with this image: DuckDuckGo.com is still tiny compared to the top four, at roughly 45 million searches per month.\u00a0 But it is growing rapidly in recent months as concern over Google's privacy policies have grown.\u00a0 Here is the Duck Duck Go traffic chart: Click for milestone explanations of above traffic chart Blekko Blekko is a search engine launched in late 2010 that emphasizes quality of search results, over quantity. \u00a0Blekko says it excludes sites from its index that are low quality or designed "solely to game search engines." Blekko uses human feedback from users, who tag pages so that returned results include only quality content that is spam free. \u00a0Most users will jump for joy at the absence of most scraper sites. \u00a0However, Blekko's human-system tends to\u00a0exclude or give a low rank to results that others consider relevant and useful, particularly on topics its users may not be all that familiar with. \u00a0(For instance, on small business topics its results may be overly restrictive -- and less useful than Google or Bing.) But they get high marks for having a comparison engine where you can compare Google, Bing and Blekko results for particular keywords. \u00a0Blekko also gives a lot of SEO data about sites (not just your own). In September of 2011 Blekko closed a $30 Million funding round with Yandex, the leading Russian search engine, as an \u00a0investor. Gibiru\u00a0 This is a search engine that claims to be anonymous and uncensored.\u00a0 Actual queries are handled by a modified Google algorithm, but the company says results are not targeted or filtered, and that tracking is limited. \u00a0For those especially concerned about privacy, you might want to give Gibiru\u00a0 a whirl. Conclusion If you play the odds as a website owner, you'll place most of your attention on Google, and then Bing. \u00a0Invest some effort to make sure your site does as well as possible in both. \u00a0Remember, search engine optimization is a marathon, not a sprint \u00a0-- so look to be in it for the long haul. As a searcher, if privacy is a big concern, or the absence of spam results is important, you may wish to check out Duck Duck Go, Blekko or Gibiru.