The social network is exploring the possibility of charging users $1 when they send an instant message to somebody who does not appear on their friends list.
Mark Zuckerberg's firm made their announcement via its online newsroom, and was quick to stress that only a small number of account holders in the US are testing the service.
"Today we're starting a small experiment to test the usefulness of economic signals to determine relevance. This test will give a small number of people the option to pay to have a message routed to the Inbox rather than the Other folder of a recipient that they are not connected with," read a statement from Facebook.
The company went on to say that profit from the service will be invested in improvements for the website, but also insisted there will be benefits for users.
"Several commentators and researchers have noted that imposing a financial cost on the sender may be the most effective way to discourage unwanted messages and facilitate delivery of messages that are relevant and useful," the statement continued.
The move marks the first time Facebook has attempted to charge for any of its services.