Advertisers have access to what you do online — targeted ads come from your emails, web searches, and the websites you visit. But your photos have been largely off limits — until now. A company called Ditto is now scanning photos posted to social media sites like Facebook, Twitter and Instagram for branded products and selling that information to companies and advertisers.

“We train algorithms to find mostly brands that are in photos: the drinks that people are holding, the brands that people are wearing, handbags and other things that appear frequently in photos,” says David Rose, CEO of Ditto. “Those are very interesting to companies that sell the product because they can see how the product is actually being used in the wild.”

The primary use of Ditto so far is what Rose calls “digital ethnography,” or using photos to help brands see how their products are used and with what other products they’re used with. “For example, if somebody’s holding a Red Bull what are they wearing?" says Rose.

Tumblr (which Yahoo is the parent company of) recently inked a partnership with Ditto to allow the company to analyze all 130 million photos shared daily on the website.

While Ditto may be able to better target advertising to consumers there’s certainly a privacy issue at play. To have a company analyze personal photos for large corporations certainly seems like a violation of personal space.

“We don’t do any analysis of private photos so this is really about photos in the public domain that people have voluntarily opted into sharing,” says Rose.

Rose also draws a parallel between text and photo analytics. “There are companies that are reading your Tweets and trying to be useful to brands,” he says. “Since most of the conversation right now is happening through photos this gives brands a chance to see what people are interested in.”

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