On reading a recent post in The Borderless Communicator it finally became clear to me why Skype insists on spewing the ridiculous "309 million users" claim everywhere. Anyone who has taken even a superficial look at it can immediately see that this claim is patently false, so why would they keep repeating it, and make themselves look stupid? Because what they are really trying to do is conceal the fact that acceptance and use of Skype with new users has been rapidly declining.
The numbers presented in The Borderless Communicator are convincing, but I disagree with their conclusion. They suggest that the reason is that new Skype users are dissatisfied with Skype support (and thus must be dissatisfied with Skype itself, if they need support to begin with). I agree with that, as far as it goes. But I think a much larger factor is that Skype is not being tried at all by anywhere near the number of "new users" that the statistics would imply. I believe that the overwhelming majority of new Skype accounts created every day are in fact "throw-away" accounts created by the spammers and pornographers who now infest the Skype user space, and flood Skype users with contact requests and chat. Those accounts are created, used once (or a very small number of times and/or for a very limited period), and then discarded and never touched again.
How many of these are created every day? Thousands? Tens of thousands? Hundreds of thousands? Who knows? The Skype Cheerleading Squad (aka The Skype Journal) published detailed instructions on how to set up such a spamming system not long ago, so it is a safe bet that anyone with an interest in doing it can easily find out how. Skype is obviously very happy with the situation, as it tremendously inflates the number of "registered users", and helps them mask the fact that their real uptake and acceptance by new users has probably been declining for several years now.