The social news concept is built on the idea of information cascades, not only in its mechanics, but also in its rise to popularity and manipulation strategies.  Social news websites, such as digg.com and reddit.com, allow anyone to post a link to an external website along with a title and a short description.  Users who log in can give one vote to a particular link/story if he or she thinks it is worthwhile.  If the item garners enough votes within a certain amount of time, the item gets pushed to the front page, where it can be seen by anyone visiting the homepage of the site, thereby pushing the item past the tipping point and causing a cascade.

If a particular article has many votes, it is likely to get more attention than an article with fewer votes, especially since users often take advantage of the sites’ sorting features, where one can view articles by number of votes for a particular time period (such as top stories in 24 hrs, 7 days, 1 year, etc.).

New stories start with one vote.  A vast majority of new stories never get more than their one initial vote, since there are often thousands of new submissions every day.  However, when a new story gets more than one vote, it often attracts the attention of others looking for interesting, new stories/articles and will frequently get more votes after obtaining that second vote.  Therefore, you often don’t see too many upcoming stories with 2 or 3 votes, because if one person finds the item interesting, others will likely find it worthwhile as well.

This model of cascading popularity often gives rise to manipulation and gaming.  By manipulating the vote count of a particular article, some ambitious users could artificially promote their item to the front page, even if it doesn’t deserve most of its votes.  One of the most common ways this is done is by creating multiple accounts on different computers (or using proxies) and voting on your own article using those false accounts.  Another way is by secretly creating support groups where members mutually agree to vote on each others’ articles.  Once an item gets a certain amount of artificial votes, it will attract the attention of genuine users, often leading them to believe that the article is legitimately worthwhile, thereby manipulating the opinion of others using contrived methods.

Now, this manipulation strategy does not always work, since most users are aware that such manipulation exists, and will be quick to realize if a particular story is not worthy of its votes.  Most social news sites have built-in protections against gaming strategies.  They often keep their front-page-promotion algorithm top secret, making it more difficult to falsely promote an article, or they keep track of IP addresses and geolocations and create blocklists for users that often vote in local clusters.

Another question regarding social news sites and cascades is how a particular social news site rises to popularity, while some others struggle to attract users.  Most social news sites do not have any substantial form of advertising and are rarely linked to directly, since they are themselves link-hubs to external websites.  One of the most popular social news sites, digg.com, has for some reason been able attract more users than any other social news site(1) (according to its Alexa ranking of 135).  Digg will often have links to articles that gather more than 5,000 votes in one day, whereas some of its closest competitors, such as AOL/Netscape’s Propeller.com and Mixx.com will often get no more than 300 votes for its most popular story of the day.

What causes certain social news sites to succeed and others to fail?  Digg.com has never really advertised their site, although its founder was once a minor celebrity on a small-time, now-cancelled TV network (Tech TV), which may have provided the small, initial boost needed to reach past its tipping point.  On the other hand, the social news sites backed by large companies, such as AOL/Netscape’s Propeller.com and Yahoo Buzz have never been able to match the size of Digg’s community, despite their highly recognizable company names.

Perhaps Digg’s early entry onto the social news scene helped to start building for a cascade before other social news sites, or perhaps Digg’s initial popularity was a direct result of the founder’s small early fan base, or perhaps there was some gaming on the part of the Digg team, manipulating their own numbers to give off the impression that the community was larger than it actually was in its early stages.  Whatever the case, one thing is certain: Digg understands the cascade model and uses it to its advantage.  Either that, or they have been really lucky.

(1) http://piggybankpie.com/social-media/the-25-most-popular-social-media-news-websites/ | (Google Cache)