Wednesday, April 22, 2009

Amazon has an Integrated URL Shortener - AMZN.COM

Kyle Mulka just tweeted an AMZN.COM url to a product page. I was amazed that this didn't get converted to a longer URL, but that Amazon allows for this alternate page representation. Here's an example:

I started playing with a number of other shortcuts besides product codes and found some other URL's that do redirect to other URL's:

Interestingly, I note that almost no one seems to be twittering these short URL's directly (less than one per day on Twitter right now - and only 15 people have sent updates including them in the last two weeks).

I also note that Google does not have any pages in it's search index using the domain.

As Twitter becomes more popular, I think more sites will be incorporating URL shorteners into their applications, enabling their users to share their pages without resorting to 3rd party services. Amazon's tool, like Digg's "Digg Bar", is also a handy address-bar shortcut; I can envision training myself to type instead of visiting and then navigating to the kindle section.

Update: Analysis of AMZN.COM shortcuts

My curiosity piqued, I decided to see what mysteries lay behind the AMZN.COM domain. I wrote a program to search through an English dictionary looking for valid shortcuts. I found that they break down into a few distinct categories.

Feature Pages

The biggest category (496 shortcuts) I found are "feature" pages. These seem to be highly customized pages about a collection of product types. I'm assuming these are hand crafted by Amazon's editors.

accessories, adobe, ads, advertise, advertising, airborne, aldo, allied, angel, apparel, apple, archery, artisan, artists, arts, ati, atlanta, atlantis, att, austin, auto, automotive, autos, av, avon, baby, badminton, baking, ballet, bargain, bargains, baseball, basket, basketball, beauty, bedding, benefit, bernardo, beverages, bibles, blackberry, blankets, bleachers, blizzard, block, boating, bob, bodybuilding, bolt, bombay, books, borders, bosch, boss, bostitch, bostonian, brass, braun, broadband, broadway, brother, business, calendars, camera, cameras, camping, campus, canning, cannon, canon, car, careers, cars, catcher, cellular, celtic, champs, charities, charity, chat, cheap, chicago, chocolate, choice, christian, christianity, christy, citizen, classical, clearance, clifford, climbing, clothes, clothing, coffee, college, columbia, comics, command, computer, computers, concert, concord, condiments, confessions, construction, contractor, cooking, corporate, costume, costumes, country, crafts, crane, creative, crew, cricket, criterion, dallas, dance, decca, decks, decor, delta, denver, detroit, diamonds, discount, discounts, diving, dolls, dove, drapers, drugstore, drums, dummies, easter, eastman, educational, ei, electronics, emerging, engagement, engineering, entertaining, entertainment, essentials, et, exercise, eyewitness, fans, fantasy, faulkner, feed, feeding, fencing, festivals, financial, financing, fishing, fitness, flash, flashlight, flip, flowers, focus, food, football, footprint, footwear, fossil, fox, fragrance, fragrances, franklin, fresco, freud, fuji, furniture, galaxy, games, gaming, garden, gardening, gateway, gear, gilbert, ginkgo, giving, global, golf, gourmet, gps, graduation, green, griffin, grizzly, groceries, grocery, guess, guitars, gymnastics, hallmark, halloween, halo, hannah, hannibal, hardware, harry, health, hearts, heaters, hefty, hi, hiking, hips, history, hitchcock, hobbies, hobby, hockey, holmes, home, hoover, horizon, horror, household, hue, hulk, hunting, ice, indies, industrial, ink, insomnia, instruments, ironing, irwin, isi, jazz, jello, jet, jewelry, jobs, journey, kaiser, kids, kitchen, kraft, landscaping, latin, leadership, leapfrog, learning, leatherman, lee, levels, levis, librarian, libraries, licensing, lighting, literature, lodge, lucky, lush, macintosh, magazines, majestic, marvel, maverick, may, meats, medical, memory, metal, method, mi, microwaves, milwaukee, mini, minneapolis, mixers, monster, monsters, motorcycle, movies, mozart, murray, music, nabisco, nara, nautilus, naxos, nec, nfl, nick, nikko, nonfiction, nordstrom, notebooks, nuance, nursery, nursing, observer, office, olympics, olympus, oneida, oracle, organic, orvis, oshkosh, outdoors, outlet, paint, palm, paramount, parsons, parts, patio, patrician, patton, pc, pearls, penny, performance, pets, philadelphia, phillips, philosophy, phoenix, photo, pillows, planters, plumbing, po, polar, polaroid, polo, pools, practices, prepare, preschool, presto, princess, processing, professional, progressive, projects, puma, puzzles, pyrex, read, reese, reference, relic, religion, remington, replacements, resolutions, revere, ricci, rival, rockport, rocks, rodeo, romance, roots, rousseau, royal, rpg, ruby, running, russell, safety, sage, sale, salter, sandpaper, sands, sante, sauces, save, scholastic, science, scientific, seafood, seattle, security, sees, services, sesame, sewing, sex, shakespeare, sharp, shoes, shorts, shun, silhouettes, silver, simmons, simplicity, singer, skating, sledding, snacks, soccer, software, solutions, spanish, spices, sports, spreads, spring, squash, stanley, stones, storage, strings, summer, sunbeam, sunshine, survivor, swimming, switch, tang, tape, target, taxes, tech, teens, television, tennis, textbook, textbooks, thanks, theater, thomas, timex, toner, tools, topics, torino, toys, training, transformers, travel, trinity, triumph, truck, trucks, trump, tuna, tuttle, tv, twilight, umbra, universal, university, unlocked, upgrade, urban, used, verve, video, vikings, vinyl, vivo, viz, volleyball, vs, wallace, warner, watches, waterskiing, weber, werner, west, westinghouse, wheeled, wheels, wiley, winds, wire, wireless, wood, woodworking, wrangler, wrestling, write, xerox, yoga, zenith, microsoft

Product Pages

For some reason, Amazon has chosen to create shortcuts to individual products in their catalog. I found 100 shortcuts in this category.

america, apartment, arthur, badlands, balls, barrels, barry, beans, beats, body, bottom, brazil, breakaway, breakthrough, buckets, century, chaplin, chef, commitment, confidence, conversations, cookie, corner, cracker, dash, dating, deadline, deceit, details, dow, drawing, dungeon, eades, earl, espionage, evolve, excel, fish, fit, garcia, gunslinger, hillman, hive, icon, inclusion, indispensable, inspire, intrusion, israel, joss, kimball, kindle, leo, loopholes, millionaire, mira, mummy, noel, nostradamus, nourish, oasis, organizing, oyster, palmer, paralysis, passion, passionate, peacock, persuasion, poe, portfolio, presence, profitable, prosper, revved, santa, sarah, screenplay, seal, self, selling, service, ship, sloan, spies, startup, stocks, stranger, swimsuit, talent, toxic, traveler, waste, we, whistle, wind, winners, wired, wizard, wolves

Sports Team Pages

I found 178 custom pages dedicated to products related to sports or sports teams.

aggies, akron, alabama, angels, arizona, arkansas, army, arsenal, athletics, auburn, avalanche, baylor, bears, bills, blues, bradley, braves, brewers, broncos, brown, bucks, buffalo, buffaloes, bulls, butler, cal, california, campbell, capitals, cardinals, centenary, charleston, chiefs, cincinnati, citadel, colorado, colts, connecticut, cornell, cowboys, coyotes, creighton, cubs, dartmouth, davidson, delaware, devils, dodgers, dolphins, drake, drexel, ducks, duke, eagles, evansville, flames, florida, flyers, georgetown, georgia, giants, hampton, hartford, harvard, hawaii, hawks, heat, hoops, houston, howard, idaho, illinois, indiana, indians, iowa, irish, islanders, jacksonville, jets, kansas, kentucky, kings, lafayette, lamar, liberty, lightning, lions, longhorns, louisville, magic, maine, manhattan, marquette, marshall, maryland, massachusetts, mavericks, memphis, mercer, mets, miami, michigan, minnesota, mississippi, missouri, monmouth, montana, nationals, navy, nebraska, nets, nevada, niagara, northeastern, northwestern, ohio, oilers, oklahoma, orange, oregon, orioles, pacers, pacific, packers, panthers, patriots, pennsylvania, phillies, pirates, pistons, pittsburgh, portland, princeton, providence, raiders, rangers, rays, reds, rice, richmond, rider, rockets, rockies, saints, senators, sharks, southern, spurs, stanford, stars, steelers, stetson, suns, syracuse, temple, tennessee, texans, texas, tigers, titans, tulane, tulsa, twins, ucla, utah, vermont, virginia, volunteers, wagner, warriors, washington, wild, winthrop, wisconsin, wyoming, xavier, yale, yankees

Search Pages

14 pages are shortcuts for product searches.

bowman, browning, buckley, choose, converse, curling, lauder, olympic, pickup, plot, poker, razor, rink, slugger, steiner, thermostat, thermostats, wilson


20 additional shortcuts send users to pages not on the primary domain.

affiliates, associates, auction, cell, de, developer, fresh, investor, meters, news, phrase, phrased, phrasemaking, phraseology, phrases, pr, press, queue, soap, wine


114 shortcuts defied categorization. They are generally special features of the Amazon web site.

access, advantage, agreement, anywhere, atonement, audible, bach, bank, barney, bill, birthday, blacks, cancel, capote, card, cards, cart, chronicle, claim, claims, classics, communications, connect, contact, coop, current, dad, daily, deals, delivers, direct, directory, discover, education, environment, episodes, feedback, garage, gifts, goldberg, greenwood, habitat, hd, heart, help, holiday, honor, horton, howell, images, inaugural, inauguration, international, jaws, journeys, kaplan, labels, library, lippincott, locker, marketing, marketplace, martian, mcgraw, mobile, mom, montreux, morningstar, nolo, nonprofit, occasions, orders, packaging, passes, password, phone, pin, pioneer, prime, privacy, productivity, publishers, push, quiver, refunds, reporting, return, returns, rewards, search, sell, shades, sos, sox, spa, studios, summons, tags, ted, today, tracking, trading, usability, valentine, vault, visa, visual, vote, wastewater, waters, wedding, wishes, zen, zing


Perhaps most interestingly, I found 68 shortcuts that no longer seem to function specially (they default to the home page), or they reference a secured page not intended for Amazon customers

alerts, alien, ash, awards, beta, blocks, board, brooks, buick, community, credit, dell, documents, egghead, errors, es, evening, exec, favorites, fiesta, friends, game, ginger, go, ibm, input, java, join, lifetime, local, manage, mutter, new, orchestras, phantom, preferences, profile, recommendations, reminders, review, reviews, schwab, sellers, star, status, store, tag, text, traffic, wolf, yellow,
anniversary, communities, continue, damages, dexter, discussion, discussions, dylan, forum, forums, japan, japanese, links, madonna, mae, patents, supernatural

Monday, April 13, 2009

Time-Score - A New Algorithm for Calculating Time-Weighted Scores

One of the reasons I created was as a test platform for a new social scoring algorithm I've developed called "Time-Score". You'll note that calculates the most popular links on the site and updates it real-time.

Each time a user interacts with content on, the site accumulates points as follows:

  • Sharing a Link - 2 points.
  • Favoriting an Link - 2 points.
  • Commenting on a Link - 7 points.
  • Viewing a Link - 1 point.

By time-weighting the scores, actions taken today are twice as valuable as actions taken yesterday (we say the "half-life" of a link-score is 1 day). So, if 100 people visit a link today, it will rise to the top of the popular list (with over 100 points). By the same time tomorrow, the score will have decayed to just over 50 points if no further people visit the link. Each day, it will be cut in half, so that after a week, it will effectively have less than 1 point, and more recently active links will rise to the top of the popularity list.

This ensures that the most popular links have to continually get the attention of the audience to stay at the top. This scoring algorithm also applies to every tag applied to links. For example, the most popular videos are shown using the same scoring algorithm.

I'm applying for a patent for this algorithm now, as I think it has several advantages over other scoring algorithms that I've seen or implemented in the past:

  • Real-time updates - Scores are instantaneously updated and can be compared against all other scoring values in the database.
  • No Batch Processing - The scoring decay function (half-life) does not require any batch processing of older scores to normalize them for subsequent days.
  • Combines scoring events at distinct times - There is a well defined relation to combine scores at different times, based on the characteristic half-life of the score.

Since most sites don't publish how they do popularity ranking, I can't be sure if my algorithm is unique. Blog posts about Reddit's algorithm indicate some similarity - but they lack a mechanism to combine scoring events at different times (they calculate all events as if they occurred at the time the post was first submitted).

The code for the Time-Score algorithm is quite simple. I have granted a royalty-free license for all non-commercial users. If you're interested in licensing this technology for your commercial application, please contact me at

Wednesday, April 8, 2009

Exhaustive List of URL Shorteners started as a small hobby project, and has grown in scope as I've found many possible features to add.

There are a wide variety of Link Shorteners in the market today. The first products appeared in 2001, and people have used them to shorten 100's of millions of URL's to date. With the advent of micro-blogging sites, like Twitter, the demand for URL shorteners has grown even greater.

TinyURL is the first URL Shortener to gain wide popularity. Started in 2002 by Kevin "Gilby" Gilbertson, TinyURL remains the single most popular URL Shortening service, with a claimed 145 million links shortened to date, and 1.5 billion clicks per month (nearly 600 per second) on their shortened links (as of January, 2009).

There are a number of reasons why people are using URL Shorteners:

  • Fixing Links - Original links may be too long to fit on a single line in an email message, causing some email clients to wrap them, making the link unusable.
  • Beautifying Links -Original links are long and ugly - a shorter one looks better in email or IM messages.
  • Space requirements - Twitter messages only allow 140 characters - long URL's won't fit, or don't allow enough explanatory text to accompany a shared link.
  • Spam and Phishing - Spammers sometimes use URL Shorteners to disguise the true destination of a link. They can claim it will take a reader to one destination, when if fact it goes to another. This can make it more difficult for spam filters to recognize spam messages, and can also fool users into falling for a phishing scheme.
  • Link Tracking - Individuals and marketers who are sharing links, often like to know how many people are clicking their link, or know what site people are clicking from.

TinyURL defined the baseline functionality by which we can judge follow on competitors. As an early entrant, the feature set is basic, with a couple advanced features.

  • Redirection - Redirects from a short URL back to the original.
  • Web Form - Type a link into a web form to shorten it.
  • Custom Alias - Select your own text (if available) for a tiny link (e.g.
  • Bookmarklet - Install a bookmarklet to create a short URL from the current page.
  • Relative Redirection - TinyURL links can be appended by additional URL path text to redirect to a "sub page" of the original shortned URL.
  • Link Preview - Turn on preview mode (remembered by cookie) to display the target link BEFORE redirecting to it (used to confirm link is not spam, adult, or phishing).
  • API - TinyURL supports a simple web request that will return the tiny URL from a long link - very simple but it works for many applications, for example Twhirl.

In a future post, I'll review the most popular (stand-alone) URL Shorteners (and throw in a comparison to the service as well); sites that do URL shortening as an added feature (e.g., FriendFeed's "") will not be considered.

"Complete" List of URL Shorteners

The following list is EVERY URL shortener I have found to date (and I'll update it as I find more - if you know of additional shorteners, please send mail to As a measure of their relative popularity, they are listed in order of their published Alexa Ranking (most as or Jan 2009, but some updated in Apr 2009). The sites that are highlighted will be the subject of my next post - a competitive review of the features of the most popular URL Shorteners.

Update 1: I've estimated the number of Tweets per Day that each service is being used to send. The front runners on the list are sorted by that statistic, rather than Alexa rank as it seems a purer measure of popularity.

Update 2: Twitter Rate numbers from May 2009 - also showing relative change in rank of each shortener from last statistics in April.

Update 3: Updated June 11, 2009. Note Stumble Upon's new shortener is already getting lots of mentions on twitter, even though it's still in limited beta.

The LAST Update: I'm going to post updated stats in a fresh blog posts from now on.

Thanks to Chris Koss for doing the competitive research for this post.