There is no guarantee that a deal between WhatsApp and Google can be hammered out. Last December the two were said to be discussing an acquisition which never made it past the talking stage. At that time, Facebook was also said to be interested in the messaging app. Users of WhatsApp pay $1 for the service with iOS users paying at the time of download while Android users pay after a free first year. Not only is it the second most popular paid app in the Apple App Store, it carried an incredible 18 billion messages on New Year's Eve. Some estimates have the app pulling in about $100 million a year in revenue.