WhatsApp now has 1.5 billion monthly active users (MAUs) who are exchanging nearly 60 billion messages on a single day, Facebook CEO Mark Zuckerberg announced on Thursday.In an earnings call after announcing the fourth quarter results, Zuckerberg said that Facebook-owned Instagram is now the most popular Story-sharing product, followed by WhatsApp.Both Instagram "Stories" and WhatsApp "Status" features now have 300 million daily active users (DAUs) -- compared to 178 million Snapchat users, TechCrunch reported.On February 19, 2014, Facebook acquired WhatsApp for $19 billion, its largest acquisition to date.WhatsApp currently has over 200 million monthly active users in India.To help businesses communicate better with their customers in India, WhatsApp last month officially rolled out "WhatsApp Business" -- a free-to-download Android app for small businesses -- in the country.The new app, available on Google Play Store, will make it easier for companies to connect with customers and more convenient for its users to chat with businesses that matter to them.In India, 84 per cent of SMBs think that WhatsApp helps them communicate with customers and 80 per cent of SMBs think that WhatsApp helps them grow their business.