SAN FRANCISCO —  Facebook‘s instant messaging service isn’t just for sending smiley faces and photos anymore. Now you can use it to send money instantly to your friends.

Facebook, the social networking company, announced Tuesday that American users of its Messenger app would be able to link their debit cards to the service and use it to message money to one another just as easily as they send a snapshot or text.

Given Facebook’s huge size and reach, the introduction of its payments feature — which has been highly anticipated by Wall Street — is likely to cause tremors in the nascent market for instantly sending money to individuals, known as peer-to-peer payments.

And analysts said that if the payment system succeeded, Facebook would extend it to other types of purchases, such as consumers’ buying of products directly from advertisers. 

“Facebook could use this as a back door to get people’s debit cards to enable the buy button,” said Robert Peck, an Internet analyst with SunTrust Robinson Humphrey.

WeChat, which is essentially the Facebook of China, and other Asia-based communications services like Alipay already allow their hundreds of millions of users to send money via instant message. But the technology is only beginning to appear in the United States, where email payment services like PayPal have long been more popular.