Twitter's user growth is tapering off alarmingly quickly. With an active user base of 241 million by the end of 2013, the apparent deceleration of Twitter’s growth suggests that the service will have a very hard time coming close to Facebook’s user base, let alone matching it.
When Mark Zuckerberg was asked why his company had acquired WhatsApp for $19 billion last week, he replied that services whith the potential to reach a billion users are hard to come by. It seems like Twitter isn't one of them.
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