What's the cost of Twitter ?

According to this post from Pat Phelan and Florian Seroussi from Roam4free Twitter would cost the economy around $13,5 billion in 2008. Let's have a look at their assumptions.

750.000 registered users
Today Twitdir reported 753.629 users. These are only Twitter users with a public profile. Twitter users with a private profile (estimated at 15%) have to be added, giving 866.673 users.

450.000 active users
Based on a large number of Twitter users analyzed, I did find out that 45% did not post a single message over the last 30 days, 40% did post at least one message in the last 7 days. 40% of 866.673 gives 346.669 active users.

As I sometimes use Twitdir (and other sources) to look for Twitter users for a geographical location, I regularly encounter Twitter users that do not exist anymore. Twitdir seems to catch (hopefully all) new Twitter users. Twitdir however does not seem to catch all abandoners. So the figure of 346.669 active Twitter users is too high. If the number of dead accounts is 15%, we finally end up with about 300.000 active users at this moment.

60.000 new users each month
In a recent previous post I showed a graph with the growth of the number of Twitter users. Currently there are daily over 3300 new Twitter users according tot Twitdir, resulting in 100.000 new Twitter users each month.

As said before, the number of deleted Twitter accounts is unknown. I guess that Twitter users who are not interested anymore in using Twitter do not always make the effort to actually delete their accounts. They rather leave their accounts alive, but do not post new messages nor read messages from other Twitter users. They belong to the large group of sleeping accounts. Let's suppose that the number of sleeping accounts outnumbers the number of deleted accounts.

Number of messages
The author of Tweetscan announced a while ago on his blog that Tweetscan is capturing almost 100% of all public Twitter messages. Unfortunately he did not mention how many messages Tweetscan is capturing.

In June 2007 I wrote a post to announce that Twitterment (a Twitter search engine that is currently not available anymore) detected 25.000 messages per day. As the number of Twitter users has doubled since June 2007, the number of messages will probably be higher. A safe bet is at least two to four times : 50.000 - 100.000 messages per day.

Another way of looking at Twitter activity is looking at the average number of messages per Twitter account. The average number of messages for the data I collected is 253. Only 5% of the Twitter users have produced more than 800 messages. It is also interesting to have a look at the tweet frequency, the number of Twitter messages written per day. On average the tweet frequency is 2,15 (messages per day). 5% of the Twitter users write on average more than 6 messages per day. Several of the Twitter accounts with an high tweet frequency are non-human, the messages are automatically generated (e.g. news feeds).

27 minutes per day
This amount of time seems reasonable for a heavy Twitter user, with an high tweet frequency. Not all Twitter users are heavy Twitter users, implying that 27 minutes per day is too high.

$20/hour
Although this may seem a fair productivity cost, it is probably only valid for developed countries such as the USA, Canada, the UK or Germany. Wages and labour cost in other countries are much lower. What is the average labour cost for Africa - where there is also a (very small) Twitter user base ? What is the average labour cost for South American countries such as Mexico, Brazil and Argentina with also thousands of Twitter users ?

100%
I do not agree that 100% of all Twitter activity has to be considered as a (complete) waste of time.
- Not everyone is using Twitter during work hours. Already a lot of companies are blocking Twitter forcing their employees to postpone their Twitter activities until they are at home.
- There is practical usage of Twitter, even within a business context, e.g. Remember the milk.
- Monitoring Twitter can be part of someone's job. I personally know several persons who make their living as a web developer, web consultant, social media consultant, online marketing consultant, ... This kind of job implies that you have to keep in touch with recent trends, for instance while using Twitter.


If the cost of Twitter usage to the economy would really reach $13,5 billion in a single year, which company would be interested in buying Twitter ? Especially if the companies who incur these productivity losses would try to sue Twitter for compensations.