[gomox]

Some simple use cases:

- a multisignature wallet, that requires more than one person to sign off on a transaction before it can happen.

- payment schedules or any kind of transaction that does not function exactly like a one time, full size payment (payments, debt, etc).

- more ambitious ideas, like the Slock.it ones, involve smart locks that hold funds while granting use to a resource, and only return them after access has been revoked

In all of the above the inputs are contained in the blockchain and therefore have no need for trusted oracles.

[homogeneous]

> a multisignature wallet, that requires more than one person to sign off on a transaction before it can happen.

This is possible with bitcoin isn't it? What does the added complexity of ethereum bring to the table?

> payment schedules or any kind of transaction that does not function exactly like a one time, full size payment

This also seems possible with bitcoin, but it's also a problem that has already been solved better by the traditional payment system (e.g. netflix debits my credit card every month, why would I use a cryptocurrency solution instead?)

> more ambitious ideas, like the Slock.it ones, involve smart locks that hold funds while granting use to a resource, and only return them after access has been revoked

Can you go into specifics here? I'm not really understanding. It sounds like you're describing a kind of autonomous collateral system, but I can't really think of any practical examples where this would be useful (without bringing human judgement into the mix).

[chriswarbo]

> netflix debits my credit card every month, why would I use a cryptocurrency solution instead?

Presumably you trust Netflix enough to give them your credit card details, and you trust your credit card company enough to pay them when they present you with a list of transactions they claim you made.

That's fine for such big, entrenched players; presumably you wouldn't put as much trust in some unknown, anonymous online entity. (Although presumably trust in Ethereum isn't exactly high right now)

[homogeneous]

I suppose it depends on the product, the merchant, and the cost of the subscription. Certainly, it'd be foolish to give out a credit card to a merchant I do not entirely trust, however, it seems more risky to move cryptocurrency into a contract with a merchant I do not entirely trust (and a contract I probably don't fully understand, even if I take the time to read the code) since a credit card can protect me from fraudulent and erroneous charges that are forfeited if I opt for cryptocurrency.

[gomox]

This might sound funny in light of recent events, but the idea is that a smart contract requires no trust in a 3rd party as the rules are specified within the contract and the Ethereum platform guarantees proper execution of the contract.

[homogeneous]

I understand how it works, I just don't see how it is useful in this instance. How is a smart contract helpful in the case of an online subscription service like netflix? A credit card is less work because I don't have to "refill" the contract every month and it's safer because of the added protection from fraud and erroneous charges that a credit card company guarantees.

[gomox]

For example, a smart contract might withhold $100 from an account, and grant whoever owns the private key to that account access to open a lock. When the user is done using the resource (say, a shared car or apartment or locker), he can request his money back (minus a fee for using the resource) which would render him unable to use the resource anymore (i.e. open the lock).

Basically the equivalent of a credit card collateral on a rental, minus the credit card company.

[homogeneous]

> Basically the equivalent of a credit card collateral on a rental, minus the credit card company.

I just don't see how a smart contract is helpful here since you're still relying on the owner of the resource to relinquish your funds when they are satisfied that you have returned their property in the condition they rented it to you. Whether you use cash, credit card, bitcoins or eth the power dynamics remain the same because it's ultimately up to the owner to say "ok, everything looks good, you can have your deposit back now".

[dragonwriter]

Yeah, basically any time a smart contract involves anything that isn't a digital commodity (currency or otherwise) on the same platform, you run into that kind of problem, AFAICT.

[homogeneous]

So it seems to me as well, and even when you're dealing with most kinds of digital commodities, I don't see how a smart contract is helpful. Say I bought some software from valve or microsoft or whoever; I pay (with fiat or crypto) download, install and run, if it does not function or is totally different from what is advertised, I can ask for a refund and either the merchant will honor my request or they won't, but a smart contract cannot codify this type of arrangement.

I don't want to sound like a hater, and I think as a developer it seems pretty cool that you can start receiving funds on the web without relying on a 3rd party gatekeeper, but it seems like smart contracts have pretty limited uses (not that they are useless, just very specialized)

[gomox]

A locker wouldn't have that problem, as there is nothing to break. Public bikes in many big cities don't have that problem either (i.e. there's no assessment of the returned bike). A smart car doesn't have to have it either (sensors in the car could detect crashes, for example, and interiors could be built to be tough, like many public cars already - see Paris' AutoLib).

[homogeneous]

> A locker wouldn't have that problem, as there is nothing to break.

There is also no need for collateral or a smart contract in this scenario.

> Public bikes in many big cities don't have that problem either (i.e. there's no assessment of the returned bike).

How does a smart contract improve over the current system?

> A smart car doesn't have to have it either (sensors in the car could detect crashes, for example, and interiors could be built to be tough, like many public cars already - see Paris' AutoLib)

How does a smart contract help?

In all of your examples a smart contract doesn't add anything to the equation because the merchant (or the merchant's automated centralized systems) already have the authority and capability to relinquish deposited funds.

[jsprogrammer]

>Can you go into specifics here? I'm not really understanding.

It sounds like a security deposit, of a type. For example, I had to leave one of my shoes at the front counter of a store that hosted a small gaming LAN in the back.

[homogeneous]

If that's the case then I'm confused as to where the cryptocurrency comes in. A security deposit works just as well with fiat cash as it does with cryptocurrency and in your example there is no money exchanged at all.

[jsprogrammer]

Money is only a token of value.

What if you were unable to accept cash (for example, you are on vacation)?

Wouldn't it be useful to make a deposit on a car, right before you use it?

What hasn't been explained here, are what guarantees the depositor receives.

[homogeneous]

I just don't see how ethereum (or even bitcoin) is useful here. If you make a deposit on a rental vehicle then the deposit will be returned when you return the vehicle as it was given to you. Why is a smart contract needed?

[jsprogrammer]

When you do not want to be there to physically collect the deposit?