You might be sad to learn that Facebook sends an average of 16 percent of the things you post on Facebook to your friends' news feeds. Then again, you might be glad, since lots of Facebook updates can be pretty mundane, fairly annoying, or just plain gross. But on the surface it seems frustrating that so few of your pals know what you're up to, especially once you've gone to the trouble of saying those things on Facebook. Nevertheless -- and apparently, for your own good -- Facebook uses an algorithm called EdgeRank to filter out the noise from the signal. Like Google's PageRank, it's a mystery how the whole thing works, though there are countless websites and blog posts that claim to have solved the riddle.

The stat emerged from Wednesday afternoon's Facebook Marketing Conference along with a number of other interesting revelations, including but not limited to Sheryl Sandberg's love of that "Nobody knows you're a dog on the Internet" New Yorker cartoon. Afterward, Facebook's Director of Product Marketing Brian Boland explained to TechCrunch blogger Josh Constine, "No, there are pieces of content you create that are interesting, and there’s some that are not."

Remember: That stat is an average, and if you run a business, Facebook can tweak its algorithm so that your posts show up more frequently. For a (high) price of course.