The power of Buzz Marketing and Network effects:
Usually, features are released to a select group to check the acceptance of users and then rolled out to a wider audience. Mark Zuckerberg being hell-bent to destroy Snapchat made tricky decision to roll out WhatsApp-Status to everyone around the globe at the same time.
It created an immediate buzz on all social forums (whether they hated it or not) and due to a bigger base of users on WhatsApp (personal contacts) people realized consciously or unconsciously that they can reach a far bigger population of people unlike Snapchat without going through the hassle of creating new account, installing new app and finding their usernames and adding them.
Everyone posted their test-Status even if just to show their frustration. Two crucial feature updates would be to introduce categories of people for privacy and filters for fun. People might have hated it yesterday, but they will be using it tomorrow.
Coming up next: Facebook Stories