The scale of China's domestic Twitter rival, Sina's Weibo.com, puts Twitter itself in true perspective.
Around 56m accounts have been opened on Twitter, yet only an estimated 21 million users actively publish each month. Twitter's own Josh Elman, in charge of user retention, described to BusinessInsider the turning point from casual to regular user at the point where they follow 30 accounts and those people then begin following back. (Update: see end for updated Twitter stats)
Sina Weibo is in a different order of magnitude with 140 million users and 50 million active monthly users, Sina claims, with 10m new accounts signed up each month. Sina is hoping for significant revenue growth from Weibo in the next two years, reported China Daily late last month.
Photo by DigiPub on Flickr. Some rights reserved
There are some subtle differences in how Weibo is being used, particularly with the type of content being shared. HP research into Weibo reads like an introduction to the microblogging market in China, based on a 30-day analysis of 4,411 keywords on Weibo and comparison to 16.32m messages on Twitter.
The most commonly shared content on Weibo is jokes, images and video, most of which are retweets. The effect is less comment on shared comment, but there is also less sharing of news stories.
Marketing is taking off in a very big way; 60,000 accounts of Weibo are verified accounts for celebrities, sports stars and major brands.
Actor Yao Chen has 8.9 million followers and is turning down offers of 100,000 yuan (£9,600) per promotional tweet, while marketing professor Ye Feng predicts Sina's ad revenue will grow 50%a year due to enhanced marketing for brands and products using promotions and videos. He told China Daily: "Until now, the top 100 'grassroot' accounts have created profits of about 20m yuan (£1.92m) from advertisements since they opened their accounts."
Sina is learning to push campaigns out at peak times – 10 to 11.10am and 2 to 3.30pm – and is also looking at other chargeable service for brands. No doubt Twitter will be watching its development very closely.
The MIT Technology Review published some interesting data on the value of users on different networks. Based on a threshold of $2 per user as a starting point, Groupon is way ahead at $78 revenue per users, while Google has $29, Facebook $3 and Twitter $1.75.
Compare that to market capitalisation or estimated value into, Google dominates at $170bn, Facebook on $75bn while Twitter "languishes" on something around $7bn.
Update: Several readers have questioned the stats on the Business Insider piece and the rationale of determining which of those users are 'active', ie use their Twitter accounts at least once each month. Part of the reason BI published those estimates was because Twitter itself won't release active user numbers, hence BI's attempts to identify those. But for base registered account numbers we checked with Twitter - here's what they told us: