The original Hot or Not, which launched in 2000, was the precursor to today's ratings apps—a website that let strangers judge pulchritude by profile pic alone. It's so old, Mark Zuckerberg ripped off the idea to get Facebook rolling. So how did the newly relaunched version get to no. 13 in Apple's App Store? With the help of good old fashioned email spam.

According to its website and iTunes page, the new Hot or Not was released by Or Not Limited. The company boasts a perks-packed London office in the heart of Soho and has been offering iOS developers £1,000 as a bonus with their job offer, even if they turn down the job. But the corporate trail actually ends with Badoo, the enigmatic, spammy dating company owned by Russian entrepreneur Andrey Andreev, who was once called "one of the most mysterious businessmen in the West."

In April 2012, Badoo brokered a "white-label deal" to "effectively powering Hot or Not's service on its behalf," which would help get Badoo into the U.S. market.

But let's get back to the ranking for a minute. Hot or Not's sudden iOS success puts it ahead of Facebook (no. 15), Candy Crush (no. 17), and not that far behind Snapchat (no. 6). Tinder is all the way down at no. 108. That's problematic because when you look at their interfaces side-by-side they're pretty much alike. There are the "heart" and "X" icons to indicate interest, the way photos are framed to look like polaroids, as well as a messaging function. Both apps also take advantage of Facebook to log-in and automatically populate your profile with photos.

Tinder itself is updated version of the dotcom-era Hot or Not, so it's no surprise someone has tried to resurrect it under the original brand name. What's stranger is that it's working so quickly—and the shadowy company behind it.

A screenshot of this App Annie chart, taken today, shows how high Hot or Not has climbed since November. Although there have been spikes before, it's been clinging tight to the top since before December. The app is ranked fairly high in the "Overall" category in other countries as well.

We have one theory as to how they did it: spam. Since at least September, our tips@valleywag.com email address has been getting unsolicited emails telling us girls have been rating our photos—photos we never posted.

If you open the email and click on the "Find out your rating!" link, it takes you straight to the Hot or Not website. The most interesting part, however, is in the fine print. Right below the Badoo logo, familiar from all those subway ads, is a grayed out message saying you've received this email "from Badoo Trading Limited."

This might explain why we haven't seen any press on Techmeme for an app that cracked the top 10 slot. Because Badoo has been repeatedly accused of pulling this kind of outmoded spamming tactic in the past. It's the same beast as that "Someone has a crush on you!"as a crush on you!" spam from a decade back.

Of course, there's no mention of Badoo on the "About" section of Hot or Not's website. No, that fresh new company smell is a commodity in the current startup economy. So instead, if you visit the recruiting link for developers to win £1,000, Hot or Not boasts about its cool office space, nevermind the copycat features or sketchy spam.

Sam Yagan, the CEO of Match.com, which owns Tinder and recently spun out of IAC said he wasn't interested in commenting. I've reached out to Or Not Limited to ask about the similarities between the apps and Hot or Not's sudden growth and will update the post if I hear back.

Correction: The headline for this post originally stated that Hot or Not was using spam. It has been corrected in the headline and in the post. We apologize for the error.

Update: Over the weekend, Valleywag received a response from Hot or Not through Michelle Kennedy, who has been working as director of legal and business affairs for Badoo from 2011 until the present, according to this LinkedIn profile.

Kennedy said that the reason Hot or Not has been climbing the app store is "definitely not from spamming." Valleywag has been receiving emails about girls "liking" our photos because a Hot or Not account had been started with the tips@valleywag.com email address on April 7, 2006:

"Therefore it was part of the original Hot or Not database (which we later acquired). The emails sent to this account weren't unsolicited-they were emails sent to a registered user of the Hot or Not service."

She also tried to explain the relationship between Hot or Not and Badoo, although it's still not clear to me:

As you correctly mention, Hot or Not was once white labelled by Badoo. However, after demand from Hot or Not users for the service to return to it's original format, the decision was made for Hot or Not to be hived off from Badoo, and a group of creative minds decided to develop Hot or Not for 2014.

In response to follow-up questions, Kennedy said the reason that emails from Hot or Not still say Badoo Limited because it's:

"a hangover from Badoo days as it was using a Badoo template-thank you for drawing it to our attention, i'll have that updated asap."

I also asked Kennedy to explain what she meant by "hive off"

By Hive Off, I mean that a group of people, some new, some Badooers are working on Hot or Not (as a separate project from Badoo), still drawing on some the minds of Badoo for advice. We decided to hive-off Hot or Not (as I mentioned, in response to user demand for the return of the old product, following the white label) in the last quarter of last year

Regarding the similarities between Tinder and Hot or Not's newly relaunched mobile app, Kennedy said:

As you mention in your article, Hot or Not has been doing its thing forever. It even inspired FB. In fact, you probably have seen, most articles refer to Tinder as a version of Hot or Not, so I think the question should probably be the other way?

However, as you can see from even as far back as December, 2012, this what Hot or Not's website looked like, a very janky retro feel. The mobile app looks much more like Tinder, which launched in September 2012.

Kennedy would not give me the name of Hot or Not's CEO or a single employee at this "hived off" company, but she insisted there was nothing shady going on:

No secrecy-as above, part Badoo, part new faces

To contact the author of this post, please email nitasha@gawker.com.

[Chart via App Annie]