Like son, like father. As Instagram reels from the backlash over its new Terms of Use, announced — and then revised — earlier this week, its parent company Facebook has introduced a new service that's likely to be highly unpopular.

On its blog today, Facebook announced it will be testing a new feature that allows people to pay $1 for the ability to send you a message, regardless of whether you're friends or not. Previously, messages you received from strangers went into the "Other" folder you probably didn't even know existed, you were never notified and the message was easily ignored. Now, it will only be one dollar for anyone who wants to bombard your inbox with whatever they want.

"Today we're starting a small experiment to test the usefulness of economic signals to determine relevance," reads Facebook's official blog post about the change. "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."

Dangling preposition aside, this sentence is so whitewashed it may not sound like a bad thing. But it is.

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."

This is exactly the opposite of true. Letting anyone — from those paid by companies to market products to that one guy you met once at a party — send you a Facebook message is not going to "discourage unwanted messages" but encourage them.

There is some good news, however. First, Facebook makes clear this feature is "only for personal messages between individuals in the U.S." Fortunately, that means companies themselves will not be able to message you directly.

Secondly, a spokesperson for Facebook told Mashable you will be able to mark these messages as spam, they'll go to the "Other" folder and that person won't be able to reach you again.

Brace yourselves, here come the unwanted messages.

[Image via Facebook]