Language English

Launched November 1, 2010
Closed March 27, 2015

Developer Skrenta, Rich

Country of Origin US America

2010 - 2015 Blekko

Topic Universal

Region No Limitation

Technical functionalities
Semantic search
Crawler-based, algorithmic SeEn
Search Portal

Used SeEn Blekko

Older Version Internet Archive / WebCite

2010: »Did you think the search engine wars had devolved into a fight between only Google and Bing? Think again. New challenger Blekko is stepping into the fray, opening to limited beta testing today. It offers a compelling way to “slash the web” and put a particular spin on your search results. Blekko isn’t a Google-killer. Nor is Blekko positioning itself that way. But Blekko’s “slashtags” are a unique feature that may draw you in on occasions when you want to see how search results look when they’re skewed to a particular viewpoint. “We’re there for searches you can’t do elsewhere,” said Michael Markson, vice president of marketing for Blekko. “Every time you search the conservative web, we want to do that search. Or the green web, and so on.”« Source

2011: »Still, Mr. Skrenta, who sold his first company to Netscape and then was a co-founder of Topix, which aggregates local news, is staking his reputation and his investors’ money on a search engine called Mr. Skrenta pitched his investors with the notion that there is still money to be made in search because of the high price that the two big competitors get for search terms and advertising. If Blekko could get even a small part of that revenue, the investors would reap a healthy return on their money. His idea is to concentrate the search. Only a relatively small number of the Web’s total pages are visited — in the tens of millions rather than in the hundreds of billions. In his view, it should be possible to simplify a search engine so it could satisfy a vast majority of searchers. Blekko uses a search algorithm like Google’s or Bing’s but also gets humans, mostly volunteers, to identify the sites they know, trust and visit most often and to put those at the top of the search results. “The best site may not have the best S.E.O.,” Mr. Skrenta says. It is a Wikipedia model — or Huffington Post model — applied to search. Some people apparently will work for no pay if they are convinced that their efforts will help or influence others. Experts who care enough about a topic edit the results. For instance, editors trawling the health results may give a higher ranking to the Web pages written by medical experts at the Cleveland Clinic and the Mayo Clinic than those generated for eHow by writers getting paid a few dollars per piece. Using Blekko takes a little more effort. It works the way Google or Bing does, but if you want cleaner search results you must type in a slash mark and a category. The company calls them slashtags. Typing “/conservative” after “taxes,” for instance, would give you sites written from the right; “/liberal” gives you the other side. Blekko also sorts results for financial advice or sports. And it has some rather esoteric experts who have edited results for “gluten free” and “material safety data sheets,” a category containing information on the properties of myriad substances. If someone tries to game the results, an expert presumably would block the efforts. Not that there is a lot of gaming of Blekko right now. Only 750,000 unique users made searches in April. But for Blekko, it’s a big number — 30 percent more than the number of unique users who performed searches in March. So far, the S.E.O. experts haven’t taken aim at Blekko, but when they do start trying to manipulate its search results, Mr. Skrenta will know he has arrived. As he puts it, “They say that’s a problem you want to have.”« Source

2013: »Blekko, the alternative search engine that launched back in 2010, unveiled a major redesign today that uses some of its “slashtag” technology to help users go beyond the usual ten blue links on its competitors search results pages. Blekko now automatically breaks its results down into different categories of curated content. Say you are searching for “wine,” the search results page will now show you its top results and latest news about Wine, as well as expandable lists of more specific wine-related searches in categories like “alcohol,” “recipes” and “reviews.” By default, the new Blekko always shows two results for each category, but users can click on these lists to expand them and then use arrows to sidescroll to see even more results. Of course, you can also still use the usual Blekko tags as well (think “wine /Napa”). The redesign was built on top of the same API that powers Blekko’s oddly-named tablet-optimized search app Izik (pronounced “Isaac”). Thanks to this new design, Blekko’s CEO Rich Skrenta says, “Blekko search results now allow users to more quickly get to great sources of information rather than scan through a list of blue links.” In this context, it’s worth noting that Google, Bing and startups like DuckDuckGo have already gone beyond those blue links anyway, thanks to projects like Google’s Knowledge Graph and Bing’s Satori Entity Engine. The company says that it currently serves a user base of about 12.5 million users who perform about 5 million searches per day. That’s less than half a search per user per day, so it seems quite a few of these 12.5 million aren’t all that active. Skrenta, however argues that these numbers are “a great testament to our team that we’ve reached a usage level that almost no other search startup has managed to achieve in the past decade.” Under the hood, Blekko still uses its proprietary search engine, which uses its “Dynamic Inference Graph” and a large semantic database to provide users with the categorized results. Besides the launch of the mobile app, it’s been relatively quiet around Blekko lately. Maybe today’s redesign will kick off a new round of innovation and marketing around the service. Currently, however, it seems its competitor DuckDuckGo is winning the race with regard to mind share. The new design may change this, but it doesn’t strike me as a major breakthrough and it actually feels a bit cluttered.« Source

2015: »Add Blekko to the list of startup search engines that has come and now gone. A message on the Blekko home page, shown above, says that “The blekko technology and team have joined IBM Watson!” The page redirects to a post on IBM’s Smarter Planet blog, where things get a bit confusing. Blekko’s home page message gives the impression of a complete acquisition, but IBM’s post mentions the acquisition of “certain technology.” In our work to enhance the performance of cognitive computing systems, we’re constantly exploring new ways to identify, understand and make use of information from both public and private sources. Toward this end, we are excited about the acquisition of certain technology from Blekko, Inc, which closed this afternoon. This will provide access to additional content that can be infused in Watson-based products and services delivered by IBM and its partners. We’ve reached out to Blekko CEO Rich Skrenta (who tweeted the news) for clarification on what IBM is acquiring, and we’ll update this if we learn more. Blekko came out of stealth in 2008 with Skrenta promising to create a search engine with “algorithmic editorial differentiation” compared to Google. Its public search engine finally opened in 2010, launching with what the site called “slashtags” — a personalization and filtering tool that gave users control over the sites they saw in Blekko’s search results. In 2011, Blekko went on the offensive against Google over spam, launching a “spam clock” website at that counted up the one million spammy web pages that Blekko claimed were being published online every hour. This was just as the debate on content farms and Google was really heating up, and in early 2011 Blekko even announced that it was banning content farms from its index. About three weeks later, Google announced the Panda algorithm update, its own effort to combat spam in search results — by no means a response to Blekko’s announcement, but certainly indirect validation that Blekko, and others who had been complaining about the amount of spam in Google’s search index, were on to something. Blekko has remained out of the news for almost two years, though, with some of its last mentions being a search app for tablets and a joint funding round/layoffs.« Source

ELI WOLNERMAN (2013): »Blekko’s mission is the following: “Blekko is a consumer facing search engine focused on delivering high quality, relevant, spam-free search results. We believe search should be open, transparent and collaborative. For this reason we combine traditional algorithmic search with the expertise of our users and partners to eliminate spam and deliver results from only the most reputable, best quality sites. This combination creates a highly differentiated editorial search experience that is fundamentally changing search and content discovery online.” Blekko exists to help the user find pre-judged high-quality results. Blekko gives an editorial note that describes the ways in which it is a unique site that is focused on providing the user with information rather than simply matching search queries with results. For starters, Blekko finds the use of human judgment to be very important when assessing the validity of a website. For that reason, Blekko uses source-based as opposed to link-based authority. In addition, Blekko utilizes human curation for its websites so people can go to lists of sites that others have created in order to find information. Blekko also stresses the fact that it is spam free. Not only is spam absent from Blekko’s search results page, but Blekko also does not return search results from sites that are simply trying to advertise to the people who visit them. Blekko is extremely focused on providing the users with the information they are searching for, and nothing more.« Source

Bradley, Phil (May 29, 2013): »Nice to see a search engine expanding its search offerings, instead of reducing them. Blekko (slash the web) has been innovating a lot recently, and has just updated its search interface... There is a colour coded set of categories to the left of the screen, and results are organised into those curated categories. Each category can be expanded to show more results, and a right/left arrow allows searchers to move between results. The category can be reduced in size by simply clicking on it again. This new layout results in more results per page. It's nice and smooth, and I was impressed by the speed. Of course, this also means that it works well on mobile devices. (It's worth saying that this only works on web search, not video or image search). Blekko is an excellent search engine, and if you're looking for an alternative to the 'big guys', then it's worth giving this one a chance. « Source


Critical points

Features & Functionality

Blekko: »Blekko’s proprietary technology operates on a unique system that intersects our own original search index, Dynamic Inference Graph (DIG) algorithm, and editorial evaluation. Using the text from the Web stored in our datacenter, we distill the text and links down to a small semantic database, and use that database to map queries to a large list of editorially-crafted slashtag filters.« Source


»Search engines have been trying to divide results into meaningful categories — something better than “web, images, or news” — for many years without success. A few experimental search engines showed a list of categories on the left-hand side of the screen, and users rarely clicked on them to see what was inside. Now that the iPad has enabled easy horizontal and vertical swiping and scrolling, the user interface for exploring multiple categories of results is much easier and prettier. izik takes Source

References & further Publications

Wikipedia (EN):
Wikipedia (Others):

Other Sources

There’s No Such Thing As A Google Killer URL:
Skrentablog: Weblog ofRich Skrenta (Founder and CEO of Blekko) URL:
Blekko: New Search Engine Lets You “Spin” The Web URL:
Blekko, The “Slashtag” Search Engine, Goes Live URL:
Cracking the Search Category Problem URL:
Searching without PageRank URL:
Goodbye Blekko: Search Engine Joins IBM’s Watson Team URL:
An Engine’s Tall Order: Streamline the Search URL:
Alternative Search Engine Blekko Launches Major Redesign In Effort To Go Beyond The Usual 10 Blue Links URL:
Bradley, Phil (May 29, 2013): Blekko improves and innovates again URL:
Alexia Tsotsis (2010): What Can You Do On Blekko That You Can’t Do On Google? URL:

Created: 2013-01-22