And I disagree as usual :) Reputation is actually the one oft-cited blockchain use case where blockchains are _not_ particularly useful. The reason is simple: status is not tradeable. Each individual's status/reputation is simply the sum of other people's opinions about them, and people have the ability to change their opinions at any time. The whole point of money is that once you spend it you can't take it back. The whole point of reputation is that when you assign someone reputation you _can_ take it back. If you want to know someone's reputation, you just ask other people/bots what they think about them via network messages. The only reason we care about _on-blockchain reputation_ for Ethereum is so that good old blockchain-based DACs can use the reputation securely.

You tried to make an argument in favor of Truthcoin, and instead you ended up advocating Codius.

So what's the purpose of blockchains? Simple: blockchains are useful for decentralized consensus on databases that update themselves according to non-commutative (ie. order-dependent) state transition functions. Currency and names are two use cases. Intermediate state of business relationships is a third. Timestamping events is a fourth. There is an exponentially infinite number of non-commutative state transition functions; at this point I'm not going to agree with anyone that claims anything close to an exhaustive categorization.

In a world with IT/crypto upgrades, and changing passwords (etc), it seems that reputation must be transferable across a database, and in a pseudo-private world (with only keypairs, like Bitcoin), this would imply tradeablity. The point is not to make something which *resembles the appearance* of real-world reputation, but something which *replicates the function* of real-world reputation (something that certain groups want to build up and maintain over time).

I've never heard of Codius until now, but (from what I've been reading) it seems to fall victim directly to #3.

I think you've over-simplified your "purpose", and it is instead a "definition". Where do we need a "decentralized consensus on databases" (your purpose)? As I point out, the contents of the hard drive of *someone else* usually don't affect you, nor do shoddy business practices at places where *other people* shop. The Satoshian PoW-Clock can provide secure time-stamping (only while the miners get paid in something they can use), but there are many ways of timestamping.

> The point is not to make something which *resembles the appearance* of real-world reputation, but something which *replicates the function* of real-world reputation (something that certain groups want to build up and maintain over time).

Reputation has two purposes. First, it's a sort of poor man's security deposit: McDonalds knows to heavily police their food safety practices because if they don't and they have an incident, then they'll get a big takedown in the media and lose a significant portion of customers overnight. Knowing this, consumers are more likely to shop at places that have good reputations, and knowing this stores strongly desire to keep their reputations - one of those funny self-enforcing metastable equilibria. Second, reputation is a predictor of personality traits (or in an institution's case, governance practices) and hence behavior. Intra-protocol tradeable reputation keeps the first function but loses the second. However, if you just care about the first function, then in the cryptocurrency day and age it may make more sense to just use a plain old security deposit - which is what truthcoin reputation actually is.

> The point is not to make something which *resembles the appearance* of real-world reputation, but something which *replicates the function*

Not sure what the appearance/function distinction that you are trying to make is.

Reputation is far more than a poor man's security deposit. Debt and Equity are very different. Equity is far more flexible than debt, and in times of crises, debt-to-equity-conversions are often the best saving throw (for everyone involved). In fact, in a few ways, debt IS equity because the repayments are a function of the borrower's competence, so a security deposit is more like a poor man's reputation.

Your silk road caption is right on the money, there's no Silk Road DAC because "coding the required functionality would take too much work". Take OpenBazaar, they are trying to use bitcoin for money, namecoin for names, and rolling their own quasi-DHT for reputation. Wouldn't it make sense to use one general-purpose blockchain for all three (money, names, and reputation)?

OpenBazaar is making progress, but its only one DApp. Other DApps would have to duplicate their effort, or be forks of OpenBazaar. Its that kind of forking (one-off duplicate codebases) which leads to code rot. What's needed is a platform for DApps, which would make it easy to create, publish, and use a wide variety of "serverless" services (ie. p2p architecture). Creating such a platform requires a lot of work (I'd even say tremendous innovation ;). And yes, it will be a lot of software, but its worth trying because of the distinct advantages a p2p architecture offers over "normal business" centrally-operated websites.

What about BitShares and the family? Do you know what happens inside NXT? What about Nubits?
What about all DApps projects being collected by cyber•Talks? http://cybertalks.org/c/dapps. It seems that you feel yourself the only guy who understand the stuff. Frankly we don't see any truth at all in your project. At least for now. And that's unclear there your truth should come from.

I actually circulated an earlier version of this essay for feedback on the Bitshares forum. It was a very productive conversation but ultimately I think my ideas survived the gauntlet. https://bitsharestalk.org/i...

As to NXT, I'm afraid the 100% premine makes NXT a non-starter, and the fact that its marketcap is below that of the statirical DogeCoin proves that there's no reason to spend any valuable time discussing it.

Nubits has good intentions but is flawed...that happens to be my next blog post, so stay tuned. Unfortunately I work full time and can only work on blog stuff about an hour per day.

re: cybertalks apps. What about them? My guess is still that, overwhelmingly (maybe not always), a business will be able to provide more value to the user than a blockchain. For the youtube example, the type of user who watches video entertainment usually finds it more psychologically comfortable to watch a video ad than make an upfront monetary payment. "Watchmybit" is focused on producers, not users, which is an obvious mistake. Youtube gets the lion's share of the ad-proceeds because it had to build and maintain the infrastructure which delivers the **user** experience (including, most importantly, the brand, and also the menu of consistent [fallback] content-options).

How about Paul Brody's reasons for choosing a blockchain-based architecture for Internet of Things infrastructure at IBM? (https://gigaom.com/2014/09/... his interview starts at 22:00). Are those honest tech/econ concerns? Or just riding the hype train?

Edit: and an update since the podcast interview https://m.youtube.com/watch...

I'm ashamed to admit I couldn't make it through the video. So much empty-suit, fluff, buzzword-nonsense. I tried to skip through to find any actual information-content, but was unsuccessful. Could you do me a huge favor and pick your "favorite" 5 minutes or something? From 19:00 he seemed to admit that he had no case.

If anything, this presentation seems to be a perfect example of mindless hype. From what I saw, he actually didn't give a single "reason for choosing a blockchain-based architecture". Just kind of described a bunch of things at random. Am I wrong?

The first questioner nails it, I think. The presenter then stalls for time while fabricating more nonsense. In fact, the Q&A period makes me feel that my views about this are actually the mainstream ("silent majority"), its just that those who "figure it out" decide to leave the conversation, and don't spend their valuable time going back to explain it to those who are still catching up.

You're not wrong, I too was disappointed by the video. There were some good insights ("we need smarter toasters"), but it often sounded like a markov chain text generator of buzzwords. I thought his answer to the question about redundancy vs scalability was sufficient: all things won't be on one single blockchain, different sets will live in their own "namespaces" (only the devices in one house would be on one chain, or all the devices in one factory, etc).

Paul Brody's interview on the Gigaom podcast was worthwhile. He expects conventional cloud platforms to be too expensive for any one device manufacturer to subsidize. Because there are so many "things"-devices, and they last for 10+ years, operating costs for a centralized cloud start to really add up (and shutting down five years down the road would infuriate device owners). Additionally, free/ad-based services are unworkable (device usage data has zero marginal cost).

The blockchain is for device-device contracts, and to enable "autonomous distributed marketplaces, not just to share money (which you could do with bitcoin)". He says to do that you need distributed transaction processing, meaning generalized database transactions, not just financial ledger transactions.

The use of Telehash (a p2p messaging protocol) complements the blockchain (in his example, after flipping a light switch, you dont want to wait for a block to confirm before the light on). As you point out, Bitmessage (also p2p messaging) is decentralized but it is not a blockchain. Its really the combination of the two (plus a third, p2p filesharing component) that yields an elegant system.