Ever wonder why you don’t get a lot of spam in your Facebook inbox? It’s because the site quietly routes messages from people you aren’t friends with into a separate folder, cryptically labeled “Other.” That works really well when it comes to sparing you from unwanted mail. But as Elizabeth Weingarten explained in Slate in 2011, Facebook’s filter sometimes works a little too well, shielding you from messages you would have actually really liked to see.

Now the social network is testing a new way to solve that problem: letting strangers pay a fee to send a message directly to your inbox. On Thursday, Mashable noticed an amusing example of the scheme in action. If you’re in the test group and you try to message Mark Zuckerberg, the site will offer you the chance to send your missive straight to his inbox — for a cool $100. A Facebook spokesperson explained last week that the company is “testing some extreme price points to see what works to filter spam.” Messages to the inboxes of less-notable personages, meanwhile, will start at $1.

Pundits have been quick to mock the pay-to-message scheme as a pathetic or desperate attempt to squeeze out a little more revenue. But they’re missing the point — and the bigger picture.

As Facebook noted in December, the test is part of a broader update to Facebook’s messaging services, which now bring together your messages, chats, text messages (via Facebook Messenger) and emails in a single conversation stream on the site. That part of the announcement was overshadowed, but it’s the key to understanding the company’s innovative new spam-filtering strategy. Both are part of a long-term grand plan to build Facebook into a do-it-all social-communications utility.