Self-quantification has gone from Silicon Valley’s secret club to something even your dad has heard about. (“Your mom just got me a FitBit! It sounds like a sex toy, but it’s not!” might just be the most troubling sentence ever written.) Forbes even took a break from wondering if this “social media thing” will ever catch on to ponder whether 2013 is the year of the quantified self.

Copyright Tim Ferris

From exercise trackers like Fitbit and the Nike Fuelband, to sleep analyzers like JawboneUp, to dog-fitness devices like FitBark, self-quantifying gadgets and apps are all the rage. There are 500 self-quantifying tools out there, many of them apps you can download for free, or for a few bucks, on iOS and Android. For marketers, this is a huge opportunity to…turn our customers into super-strength cyborgs! No, wait, that’s not it. It’s an opportunity to sell them stuff they want.

These devices and apps are a potential holy grail for marketers because they combine two key types of data: behavioral and geolocation. If you know that a user takes a morning run over the Manhattan Bridge and back every morning, passing 7-11 on his way home, you could serve him an ad for Gatorade. Or ads for new Nike shoes. Or insole supports. (New York street running can be brutal on the knees.)

Copyright CBS Interactive

Other advertising opportunities might prove a bit trickier. If people are tracking their sleep patterns through Jawbone, there’s a decent chance they have trouble sleeping. Would it creep a user out to get an ad for a sleep specialist nearby? Or one of those creepy human-shaped cuddle pillows? And would Jawbone let targeting take a step further and sell the data of people who are having trouble sleeping?

Other use cases are equally intriguing from an advertising perspective. Forbes recently wrote about Chris Barbin, CEO of cloud-computing company Appirio, who instituted a company-wide fitness competition using JawboneUp that helped 300 employees lose weight. Wouldn’t they be the perfect target for ad-tech companies?

One question—of which there are many—is how exactly to serve these ads, especially since many of these devices don’t even have screens. Serving the ads when they view the app is the most obvious and logical possibility, but could advertisers serve programmatically-placed audio ads to runners through apps like Pandora and Spotify? Certainly, I’d rather hear about a half-off breakfast sandwich a block away than a sale at Bob Benson’s discount auto when I’m waiting for the next Spotify song to come on.

And speaking of that breakfast sandwich…don’t tell my 80Bites app. It’ll be our little secret.