The deeper integration of the services' messaging features has seemed inevitable since Facebook started allowing businesses to respond to Instagram comments from Pages Manager in 2016. Instagram said last May that more than 150 million people speak with a business through its DMs every month.
The move should make customer communication somewhat easier for businesses to handle, which likely benefits Facebook as the business messaging market continues to grow and rivals including Apple seek to gain a foothold. Meanwhile, though Facebook has discussed ways to make money from messages, it doesn't currently have plans to monetize Messenger and Instagram DMs, Axios reports.
A report last month suggested that Facebook is working to unify messages across Messenger, Instagram and WhatsApp. With that in mind, perhaps Facebook will eventually add WhatsApp messages to Pages Manager too.