Then it turned out that TagCow was using humans also, leveraging Amazon Mechanical Turk to get photos tagged for cheap (to their credit, they never said one way or the other). People were paid $0.04 to tag a group of five photos.

It turns out that model doesn’t work, either. Founder Michael Droz emailed today to say “After…tagging over a million images for free we looked at our balance sheet and realized it was make money or close up shop time.”

But they didn’t close up shop. Instead, they started pitching companies on a tagging service, and at least two have now signed deals: Art.com and AutoByTel. Both use TagCow to tag images, for a fee. The company says October was a profitable month for them based on these deals.

Any site which has a lot of images can potentially benefit from having more metadata about those photos. Search results will yield much better results (and the site is better optimized for search engines in general), and perhaps a sale will be made that otherwise wouldn’t be.

TagCow, which says it can tag a million photos a day, and is looking for more customers.

They also say they’ll keep their user-facing service but are now charging a fee.

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I can’t really say much about Tuyuan yet since it’s in Chinese and there isn’t much information (translated page here), but it certainly looks like they’re trying to tackle the facial recognition problem that has destroyed many a startup.

We’ve seen Riya (now focused on ecommerce via Like.com), Ookles (never launched), and Polar Rose (in private beta for nearly a year), among others. Most recently Tagcow came on the scene, but it turns out it uses humans to tag photos, which tends to produce bad data.

Will Tuyuan be any different? We have no idea yet. But we’re contacting them to find out. More soon. Thanks for the tip, Orli.

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Users upload photos – thousands of them if they like – and within a few minutes the photos are returned with stunningly accurate descriptive keywords that facilitate searching and browsing later on. The product worked so well, and the site had so little description of the technology behind it, that I speculated that humans were doing the work in the background.

And….I was right. A reader sent in a tip that they saw the service on Amazon’s Mechanical Turk service, which is a web service that gets people to do things that are fairly hard for computers to do. TagCow is actually a perfect fit for Mechanical Turk.

Users are paid 4 cents to properly tag a group of five photos. I tagged a few photos with “TechCrunch” twenty times each, collected my 4 cents, and moved on. My guess is it would take about two minutes to properly tag the five photos. That means if you work steady and without breaks, you can make $1.20/hour. More if you are speedier.

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The problem is obvious. The solution, not so much. A trail of failed startups have tried to tackle the problem with a fairly serious application of technology, including: Riya (now focused on ecommerce via Like.com), Ookles (never launched), and Polar Rose (in private beta for nearly a year), among others.

And now suddenly TagCow appears, which allows users to upload photos and have them tagged within a few minutes. The technology appears to be “magic,” meaning there’s no explanation of it.

If there’s a mountain in the photo, it’s tagged. A dog? yep. A yellow cup? Absolutely. It does people, too. Upload an image of a person and say who it is, and all other images you upload will be tagged with that person, too. The service also integrates with Flickr and will auto tag the photos you have on the service.

Thomas Hawk, the CEO of photo site Zooomr, tried the service and declared it “really, really cool,” although he wonders how it works.

The answer is, humans do it. I note that the TagCow site is careful not to say anything about the tagging process, and never use the word “automated” or anything else that would suggests computers are doing the work. Munjal Shah, the founder of Riya/Like, agreed, noting that it recognized a witch in Thomas’ photo – he says this just isn’t something a computer can do today.

I haven’t confirmed this yet. I’ve emailed the company for a description of how the service works but have yet to hear back. Until we do, I’m betting that humans are the taggers. Note that Google has effectively thrown in the towel and uses humans for this kind of work, too.

TagCow appears to be offering the service for free, so the cost side of the business may be a problem for them down the road. And the business is definitely a little sketchy. Worried about the privacy of your data? Just don’t click on their Privacy Policy or Terms of Use: “Privacy policy is TBD.” and “Legal stuff TBD.” Not exactly a way to build confidence.

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