SAN FRANCISCO -- Facebook is still experimenting with a service which charges users to send messages directly to another user's inbox.
If you are included in the test, this may have happened to you: You want to reach out to a long-lost college chum or just want to connect with someone you met at a party. A prompt flashes on your screen to pay a buck to make sure that person gets the message.
The idea: A fee can be a powerful deterrent to spam and unwanted messages. Right now Facebook is testing different price points: $1, $10 and $15.
The experiment only involves a limited number of Facebook users in the U.S. Still, questions are popping up all over Facebook and elsewhere about how it works and why sometimes users see a prompt and sometimes they don't. So let's break it down.
First, Facebook has made some changes to how it sorts your mail. You used to set your inbox to allow messages from everyone, friends of friends or friends only. Everyone else ended up in the "other folder" that most people rarely check and some don't even know about.
Now, if your setting was to friends of friends or everyone, your setting is "basic" and you mostly still get messages in your inbox from friends and people you may know. If you restricted messages to friends only, your setting is "strict" and you mainly only see messages in your inbox from friends (with some exceptions for messages that Facebook thinks may be relevant or useful to you).
In December, Facebook started testing a new service that charges you a small fee to make sure someone gets your message. (If you want to send a message to the inbox of a Facebook VIP with millions of subscribers like Facebook Chief Executive Mark Zuckerberg, that fee might be a lot heftier).
The rationale: If you cough up some cold hard cash to send a message, Facebook knows two things: that message is important to you and it's probably not spam. Still, Facebook only lets users receive one paid message a week to reduce the possibility for abuse.
Some Facebook users are confused as to why sometimes they get a prompt to pay Facebook to send a message to someone who is not their "friend" and sometimes they don't.
First, only Facebook users taking part in the test see the prompt and only when that message would otherwise land in the "other folder." There are a couple of reasons why those Facebook users might or might not always get that prompt. Either the person they are messaging has a filter that allows friends of friends to message them or that person already received a paid message this week (and only one a week is permitted).
Not everyone likes the Facebook paid-messaging test, to put it mildly. "Facebook is trying to make me pay to message my good friend" (he or she really, really likes me, I swear) is a common complaint on Twitter.
Commented one Times reader: "I often meet people at social gatherings and meetings and random places. We agree to add each other on Facebook, but sometimes they will forget my name or need their memories refreshed. So when I send a friend add, I send along a quick Facebook message explaining how we met. About a month ago, Facebook started demanding that I pay $1 per message to someone who is not already my friend. The alternative is to have my message delivered to the person's 'other' mailbox which few people ever check. I refuse to give my credit card info to Facebook, and considering the millions of messages that travel the site per day, I consider this a complete ripoff."
Facebook has not said if it plans to roll out the test to all 1 billion-plus users. On its own, the paid messaging service is unlikely to be a major source of revenue for the Menlo Park, Calif., company. On the other hand, if Facebook decides at some point to charge businesses to message users, that could definitely be more lucrative.