The trial involving what Facebook says is a "small number of people" and initially being tested just in the United States will see the $1 messages go straight to a recipient's in box rather than the Other folder, the normal destination for all unsolicited correspondence, CNet reported Friday.
Facebook users can already send messages to anyone else on the network, even if not "friended," but depending on a user's privacy settings messages from users who are not friends usually end up in the Other folder and are often considered spam or junk mail.
"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," Facebook said in a statement.
"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 in box."
While are no pending plans to launch the trial for users in Europe it could be offered there in the future, Facebook said.