Ethereum is a global transaction computer that provides a platform for decentralized applications, like Augur (http://augur.net).
Today's systems have a centralized source of truth: corporate databases. There was no other way to build applications that involve multiple users interacting with each other, so companies built those systems and profited from providing a solution.
With Ethereum, we can write simple programs that run on thousands of computers and come to a consensus on the result. Nasdaq doesn't need to tell us the result of a trade or who owns what. We can build equivalent systems that no one controls. The result is a transfer of profits from middlemen to the rest of humanity.
Finance is easy to think about in a decentralized manner since it's all information that computers control. But these systems can apply to real world interactions as well by building reputation systems on top of this global computer. If you don't abide by the rules of the decentralized system you're participating in, your reputation score will go down and people will stop interacting with you.
In this manner, Ethereum can be used to replace every marketplace startup. Uber and Airbnb are so successful because they benefit from strong network effects. Decentralized applications also benefit from strong network effects: every new decentralized Uber application will use the data from the ones that already exist to bootstrap themselves. The user base will never splinter like it does when new centralized competitors attempt to enter the market.
Ethereum gives mankind the ability to coordinate interactions between ourselves more powerfully than ever before. Social systems that once seemed too unwieldy or too anarchic to work out might now be feasible, and they could make us wealthier and more free.
No offense, but there has to be a simpler way to explain this. It sounds like you are passionate, and after seeing the video it looks like a good idea, but it also sounds like a parody of startup culture. References to "humanity" and "mankind" don't help, even if you've used them appropriately. Your comment is useful and exact after understanding the topic, but the message isn't easy to explain. And the source of this complexity is probably that the two startups you mention haven't yet crafted a message which would be simple enough to repeat.
On a side note, I've resigned from my previous startup a month after they've changed the values to "blah blah blah advance humanity blah blah".
There's a lot of humanity problems solving talk in cryptocurrency land. I think it's because the people that run in that scene can finally glimpse what this technology can do, when wielded correctly. That said, there's still a lot to do before we replace the government with a crypto contract!
Ethereum uses a cryptocurrency under-the-hood called 'ether', which pays for 'gas': compute resources like networking, storage and compute. These resources are used in a decentralized way by programs which are capable of carrying their own cryptocurrency wallets. As long as the programs can pay for their own existence, they get to keep running on the network. Like Bitcoin, the network is comprised of a bunch of 'miners' that provide the resources for running the code. You could run a miner if you wanted to. Unlike Bitcoin, the code keeps running as long as it can pay for the resources it uses. I could write some code that does this, if I wanted to.
In theory, you could create some code, have it generate a wallet, pay the wallet, and then let the little guy go wander off onto the network doing things. BTW, this little guy I'm describing is called a DAC, for decentralized autonomous corporation (or smart contracts). The 'things' it can do are limited, but it can, in theory, pay for stuff or pay other DACs, access storage, do computations, and access the network. Keep in mind this is isn't a NodeJS application framework you are dealing with here. Ethereum is primarily designed for implementing logically governed contracts between entities that need to exchange value. It's like Bitcoin scrypt on steroids, without the possibility of a halting-state. In theory.
Fun fact: Bitcoin scrypt doesn't support loops, so it's limited in scope in what it can do with a given transaction. Not so with Ethereum.
Some people will be turned off by claims that a technology can have a significant impact on humanity at large. Others will be curious to find out whether these claims can be substantiated. My audience is the latter.
Learning how to build applications on top of Ethereum is one of the most important things an engineer can do if they want to maximize their impact on humanity. I am not ashamed of these claims, and encourage anyone who wants to debate them to email me. niran@niran.org
Could you find me an inventor in history of a technology that actually changed humanity who made such a claim before it did so? Did Google claim or even knew their search engine would change the world? Did Apple? Did Facebook? Nope. You should focus your message on why your tech is useful, not that it might save humanity, most startups don't change humanity, heck, most startups fail. So it's a bit premature to claim yours will. Don't you think?
Ethereum isn't my project. I build apps on top of it, like Augur. I'm claiming that work other people did will be pretty huge for humanity, which I consider pretty acceptable.
What questions do you have about how Ethereum is useful? I attempted to answer that question, but appreciate pointers that would make it more effective.
I think that after explaining a somewhat complex subject like how Ethereum works, you perhaps could followup with a clear example on how Ethereum solves a problem that other technologies would have a hard time doing.
Maybe you can talk how Ethereum can be useful for, if I understood the platform correctly, buying/selling a car by means of a colored coin.
Or maybe you can explain how it competes for buying/Selling money Bitcoin-style, but with the specific advanteges pointed out (e.g. you don't have to download the blockchain as far as I know, etc).
Edit: After going through a few explanations, this one came up as the one I would think of using to someone that already knows Bitcoin:
Blockchain technology, introduced by Satoshi Nakamoto with the proof-of-concept implementation of a simple value transfer system known as bitcoin, represents the best digital system we have (after the internet itself) for administering multi-user interactions without any need for centralized coordination or oversight. Effectively, a decentralized system is its own authority for enforcing the rules (e.g. 'you can only spend your money once' in bitcoin, or 'whatever rule you programmed in to your smart contract' in Ethereum)
So Bitcoin enforces a very specific rule, Ethereum generalizes by letting you specify complex rules and even composite rules on top of that.
After skimming these, I'm comfortable assuming that someone will figure it out. Blockchain architecture doesn't excite me. Decentralized applications do.
Today's systems have a centralized source of truth: corporate databases. There was no other way to build applications that involve multiple users interacting with each other, so companies built those systems and profited from providing a solution.
With Ethereum, we can write simple programs that run on thousands of computers and come to a consensus on the result. Nasdaq doesn't need to tell us the result of a trade or who owns what. We can build equivalent systems that no one controls. The result is a transfer of profits from middlemen to the rest of humanity.
Finance is easy to think about in a decentralized manner since it's all information that computers control. But these systems can apply to real world interactions as well by building reputation systems on top of this global computer. If you don't abide by the rules of the decentralized system you're participating in, your reputation score will go down and people will stop interacting with you.
In this manner, Ethereum can be used to replace every marketplace startup. Uber and Airbnb are so successful because they benefit from strong network effects. Decentralized applications also benefit from strong network effects: every new decentralized Uber application will use the data from the ones that already exist to bootstrap themselves. The user base will never splinter like it does when new centralized competitors attempt to enter the market.
Ethereum gives mankind the ability to coordinate interactions between ourselves more powerfully than ever before. Social systems that once seemed too unwieldy or too anarchic to work out might now be feasible, and they could make us wealthier and more free.