What’s $53.78 of guesswork and hope per user among internet believers? Weibo’s filing for its planned partial spin-off from its parent,

Sina, reveals it was generating 44c on average per user at the end of last year. Should its listing produce the $7bn valuation being bandied about, each of its users accounts for $54.22 of market capitalisation. Twitter users are valued at roughly $120 a piece.

However bubbly China’s internet scene appears to be, the US experience suggests it can get much frothier. Weibo’s filing claims 129.1m monthly active users. Average revenue per user jumped 90 per cent over the past year, growing at a one-fifth quarterly rate by the end of 2013. Monthly and daily average users have risen by one-third over the same period. If user numbers continue to grow at their current rate but do not generate any more in revenues (perhaps competition dents advertising rates), then by 2020 Weibo sales will have risen a compound 12 per cent a year – just over half the rate if sales per user increase at their most recent rate (surely not even the most ardent believers expect a 90 per cent growth rate to continue). Conflate the two growth rates, and sales jump a compound 60 per cent each year.