This market is so crowded, but still this offer is so lucrative that many of us will be signing up. But the catch is that, the offer isn't available for everyone. It's only for certain beta users for whom the banner is shown. By the time people realize this, they would have already signed up. However, I personally feel that WhatsApp should have given a lesser valued offer, but for all the users who sign up. We need to see how this plays!