Now, users will be able to pay $1 to route their messages to non-friends. Facebook said Thursday that it is testing the service with a small percentage of individuals - not businesses - in the US.
"For example, if you want to send a message to someone you heard speak at an event but are not friends with, or if you want to message someone about a job opportunity, you can use this feature to reach their Inbox," Facebook said in an online post.
"For the receiver, this test allows them to hear from people who have an important message to send them."
The company says charging for messages could help discourage spammers.
In October, Facebook unveiled another feature that lets users pay if they want more people to read their updates. For $7, users can promote a post to their friends, just as advertisers do.