Facebook, after losing millions in its failed IPO, has started to implement in the United States the $1 trial run of its paid messaging system scheme, where non-friends who want to contact you must pay in order for their messages land in your Inbox folder rather than in the Other folder.

The strategy, according to the Menlo Park, California-based social site, meant to keep one's inbox from getting filled up with spam messages.

Moreover, "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.

"This test is designed to address situations where neither social nor algorithmic signals are sufficient," Facebook said in a blog post.

"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."

But before Facebook users get berserk, the social site clarified the trial run is only being implemented only to a limited number of people. And should they decide to implement the paid messaging system sitewide to its more than one billion users, the only ones who will need to pay for access to it are non-friends who want to send a message directly sent to someone's Inbox rather than the Other folder.

Although the paid messaging system will initially cost $US1, Facebook admitted to plans of possibly raising prices.

Along with the trial paid messaging system, updates that included "basic" or "strict" filtering settings for inboxes were likewise introduced by Facebook.

The strict setting limits inboxes to messages from friends, while the basic setting opens the door to friends of friends.

In 2011, Facebook introduced the Other folder as warehouse for unwanted or dubious messages.

Immediately, users expressed dismay over the new scheme, with some saying the new strategy benefits potential advertisers to flood a user's inbox all by just paying the required fee.

But major bottomline really is, Mark Zuckerberg, CEO of Facebook, just invented a medium where they can milk and monetize the users, after the company took a hit after it went public.