The “Half-life” of a bitly link is about 3 hours

Hilary Mason, Chief Scientist at bit.ly, a large link shortening service, has done an analysis on some of their link data to get an idea of how long links remain “alive” or “popular”. The measure was to look at 1,000 links and graph the number of hits that a link receives over 80,000 seconds (almost a day), and then determine the point over that period where half of the total number of hits were received. From the post

So we looked at the half life of 1,000 popular bitly links and the results were surprisingly similar. The mean half life of a link on twitter is 2.8 hours, on facebook it’s 3.2 hours and via ‘direct’ sources (like email or IM clients) it’s 3.4 hours. So you can expect, on average, an extra 24 minutes of attention if you post on facebook than if you post on twitter.

Running the data yielded the following graph, showing a strong power law for Facebook, Twitter and direct links (links shared via email, and instant messengers), but a delayed curve for YouTube.

What Mason computed would more accurately be called the median rather than the half-life, since she is interested in the first point in time that divides the total number of hits for the period into two roughly equal sets. More discussion on this point is given in the comments to the post. The conclusion from the post

In general, the half life of a bitly link is about 3 hours, unless you publish your links on youtube, where you can expect about 7 hours worth of attention. Many links last a lot less than 2 hours; other more sticky links last longer than 11 hours over all the referrers. This leads us to believe that the lifespan of your link is connected more to what content it points to than on where you post it: on the social web it’s all about what you share, not where you share it!

A while back I posted on the half-life of patching vulnerabilities being 30 days and there we probably have confusion with the sample median as well. I also noted the attrition for my own links in Shark Fin posts.

How many users does Twitter have?

A nice power law looking graph from Business Insider on the properties of Twitter users, and about 175 million Twitter accounts have been registered to date. But how many of those accounts are actually active and being used? Hard to say it seems. The article reports on digging into the Twitter API and finding that

Using data that is now just one month old, he found out that…

• There were 119 million Twitter accounts following one or more other accounts.
• There were 85 million accounts with one ore more followers.

With these figures, and Twitter's claim of 175 million accounts, a little subtraction shows us that there are 56 million Twitter accounts following zero other accounts, and 90 million Twitter accounts with zero followers.

The Tab Power Law for Firefox

Mozilla has released its 2010 Q1 analyst report on the state of the internet. The report was created to "provide a high-level view of key metrics on an ongoing basis and to share some interesting insights". Well, its a little short at 12 well-spaced pages, and the summary bullets are not that exciting

• Firefox’s worldwide market share hovering near 30%
• Firefox adoption is growing most dramatically in Russia
• People start their work day earliest in Hawaii and Wyoming; latest start to the day is in New York
• People in South American like applying Personas (themes) to their browser; people in Antarctica love add-ons

For me the most interesting observation was the number of open tabs people work with in FireFox, as shown in the graph below.

Most people use 2 to 3 tabs, however the maximum observed value was over 600! Also, since the median is 2.9, over half the people use almost 3 or more tabs. The graph above clearly has a power law structure, and in this case, quite a long tail.

Twitter in the Land of Power Laws

This is my first post after a long summer holiday and I am glad to say that my blog has still been receiving a reasonable number of visits in the absence of new content, albeit some visits were barely more than a glance.

Gartner has released a collection of Hype Cycles for various technology niches, as reported by Eric Auchard at Reuters for example. The particular Hype Cycle below is for Emerging technologies (double-click to enlarge).

I was immediately surprised to see Quantum Computing registering in the Technology Trigger region, which is used to denote technologies that are 10 years or more out from acceptance. I think this is something of an understatement as I argued here.

Auchard picked up on microblogging (read Twitter) being positioned near the peak of expectations, and therefore about to experience the full G-force of descending into the Trough of Disillusionment. I am not really sure from what perspective Gartner is making this prediction, since a recent study released Sysmos shows that user growth has more than doubled this year – in fact, over 70% of Twitter users joined in 2009.

The report shows that almost every aspect of Twitter is operating under a power law. In the case of new users this power law means exponential growth, whereas for other measures the power law typically means the domination by the few. For example, 92% of people follow less than 100 other people, but 1% of people follow more than a 1000 others. Less than 1% of people have more than a 1000 followers, and more than 90% have less than 100. Interestingly, 21% of people with a registered Twitter account have never made a tweet. Most people make only one Tweet per day but just over 1% make at least 10 on average. More generally, Sysmos observed that there is a 75/5-rule in operation, meaning that 75% of activity is accounted for by 5% of the Twitter user base.

Is Gartner right then? Perhaps in the words of Neil Postman the majority of Twitter users are just “amusing themselves to death”, while a few Twitter users are really tweeting themselves to death. Where is the business case here? But as I argued in The Sub-Timed Crisis in Web 2.0, we are not heading for collapse:

Unlike our current financial structures, the web is not at threat of collapsing, though many foot soldiers will fall by the way (they see themselves as pioneers, but in fact they are easily replaced). Our informational structures are not hierarchical but relational, and as such, are much more resilient to the removal of individuals. It is not the case that there are eager underlings waiting to replace leaders – the underlings are here and functioning already.

Web 2.0 losses will largely go unnoticed. New users/readers, whose information experience begins today, are being added all constantly. They are essentially unaware of what happened last month and will remain that way. Joining is not a generational wait, no corporate ladder to be climbed. Everyone joins and progresses simultaneously. This turnover goes largely unnoticed since leavers are dwarfed by joiners.

I am quite sure that Twitter will weather the Trough of Disillusionment – in fact, it already has I would say. Gartner is as overly optimistic of Quantum Computing as it is pessimistic of Microblogging.

Related Posts

• The Flap Over Twitter
• Twitter as your Personal Content Proxy
• Twitter and Extremistan