Following Clinkle's huge, $25 million round of funding, a lot of people from Silicon Valley and beyond have been wondering the obvious: What makes another yet-to-launch mobile-payments app built by a bunch of 22-year-old Stanford dropouts worth almost as much as Alex Rodriguez's salary? Finding the answer to that question has proven particularly difficult considering the founders have been super-secretive about what their startup even does — so much so that they got TechCrunch to remove a large portion of a story about said $25 million in venture capital, some of which apparently came from Stanford professors. Now, three months after the Stanford community showered Clinkle with vague praise in the pages of The Wall Street Journal, we have some intel, by way of a leak via Valleywag's Sam Biddle, on the magnet to all that money: something called Aerolink. 

According to a Stanford pal who claims to have seen the app — ostensibly, it will help change the way we pay for things — the key to Clinkle's big backing is as follows, the source tells Biddle:

Clinkle lets you do phone to phone payments via ultrasound exchanged on the phone. This is branded as "Aerolink"

My additional suspicions:Clinkle may be partnering with Verifone to get the terminals to emit / receive the same audio signals that they're using for payment information. Looking up specs on Verifone terminals , it seems to indicate that they support audio output. Clinkle may be using this to localize the phone to the point of sale terminal. Then, they would send money to Verifone ... I'm basing this on Lucas's past discussions of working with Verifone on SMS based payments (this is before Clinkle was doing the whole ultrasound thing, they initially were a sms based payments system for dumb phones). 

In other words, Clinkle will make it so you can pay with a phone by way of a special sound, which apparently makes it a competitor to, say, Square, and Google Wallet or PayPal, because the whole transaction process gets a lot easier, which is one of the few draws for mobile-payment apps in this still nascent phase of adoption.

Other than that, Clinkle's multi-million dollar "innovation" sounds promising, but it doesn't sound like that much more than anything we've seen before. Again, Valleywag's source:

Based on what's in the app, the following features seem to be a lock for Clinkle

"Wallet" feature - this looks approximately like a paypal balance (will let you pay your friends, etc)
"Credit Card" feature - scan a credit card with your phone (it uses card.io to do this)
A Scott Forstall-esque, completely useless bound leather wallet look to polish it off
Ability to pay stores (who they are partnering with)

It all still sounds pretty vague to us. Cool, but vague. This jealousy is going nowhere.