"According to publicly available data, there are now over 10 million bitcoin wallets. Perhaps the most informative statistic of all is the transaction volume: the number of transactions has also grown impressively, from roughly 80,000 a day to more than 200,000 without showing any signs of slowing."
I have several wallets. So wallets is not equal to users. If he can give every Skype user 0.001 bitcoin, he might make 100M users of bitcoin.
that is true. but there should be several million (3-8) bitcoin users worldwide, that is not a big deal with 3500 million people on the internet.