Facebook tests paid messages to strangers

Most important messages go straight to your inbox on Facebook. But there's a second class of messages, including potential spam and notes from people not in your network, that the site's algorithms deem "less relevant."
These unlucky missives are dropped in the little-known "Other" folder, where they will often spend the remainder of their digital existence unseen, unread and unloved.

"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," says the post.
The "inbox delivery test" will be available only to select people using Facebook in the U.S. for now. Companies won't have access to the feature at this time, and people are limited to one paid outgoing message a week to minimize abuse.