Twitter came in for a lot of stick yesterday, when it released its first batch of trading results since listing on the stock market. In particular there was concern that not only was the growth rate of new subscribers low but also that no data was offered on the churn rate of subscribers who had become inactive. Business Insider has carried out some investigations into this and concludes that of the approximately one billion (actually 938 million) Twitter users out there, only 25% are “active” to the extent of posting one or more tweets a month. Business Insider do accept that there will be a considerable number of users who do not post but merely follow and read other users’ tweets.