Want to send a Facebook message to Mark Zuckerberg? It'll cost you.

Facebook is experimenting with an innovative spam-filtering scheme. 

Earlier this week, Mashable published a much-discussed report alleging that Facebook was charging users 100 bucks to message CEO Mark Zuckerberg. 

"We knew Facebook was eager for new revenue streams," Mashable's Chris Taylor quipped at the time. "We just didn't know they were this eager." 

Today comes news that Mashable was correct, in a sense: Facebook is in fact experimenting with a $100 messaging scheme, one not only involving Zuckerberg, but other high-profile Facebook users, including (according to CNN) Facebook COO Sheryl Sandburg , CFO David Ebersman, and Kevin Rose, the founder of Digg. The whole thing, Facebook tells CNN, is a kind of beta test for spam filtering measures. 

"We are testing some extreme price points to see what works to filter spam," a Facebook rep told CNN today. 

It's an interesting approach: a potential revenue generator for Facebook, and a way for the social network to allow the average user to actually reach someone like Zuckerberg, instead of seeing his or her missive drowned in a deluge of spam. Of course, it's worth noting that the $100 by no means guarantees your famous correspondent will actually answer your email; the only guarantee is that it won't be categorized as junk. 

As we reported last month, Facebook is also trying out a lower-priced "pay-for-relevance" arrangement: Beginning in December, the social network began asking some users to pay $1 to reach (non-celebrity) users outside of their circle. 

"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," Facebook announced in a press release. "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." 

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