Bram Cohen is the author of the BitTorrent protocol, the preferred method for the distribution of files using distributed networks. Here he outlines the background to BT's development and the engineering problems it was designed to resolve. Thereafter Bram discusses the reasons for the failure of pay-for-access models on the net, and explains why advertising has become the preferred form of monetization of online 'content'.
|Play from beginning
|Interview with Bram Cohen, developer of BitTorrent
|Well there's is the universe which did happen and the universe which should have happened,
|and pretty much everyone seems to agree that in the universe which should have happened,
|BitTorrent was written by some venture capital backed company
|which then got sued and kinda sort of acquired after getting sued into oblivion
|and the CEO having a scare of almost having been
|thrown in prison, or actually being thrown in prison.
|Of course in the universe which actually happened,
|- which doesn't really make any sense so it isn't really worth talking about.
|In the universe which actually happened, BitTorrent was written by some guy
|in his living room who was living off of credit cards and became explosively huge,
|prior to taking any investment whatsoever.
|And then the person who wrote it somehow wound up working with Hollywood.
|And running a very legal business without any legally scary situations.
|When you have television or radio and by that I mean television over the airwaves,
|It's kinda like someone is screaming really really loudly and everyone else can listen.
|And so anyone who wants to can tune in
|Now this is not very efficient from an energy standpoint
|and it involves some very very loud screaming.
|It is highly effective at broadcasting signals to space aliens.
|If there were any aliens hanging out around earth in the 1900s,
|they'd have had a very very easy time watching television.
|And getting a good look at our culture that way,
|because that's where most of the signal was going, was out into space.
|The internet doesn't work that way - on the internet
|you have all these machines which are connected to the net
|and you can send a message to anyone else on the net,
|but it goes to just them - there's no broadcast concept there.
|So there's this question of how do you make broadcasting work?
|Unfortunately broadcasting can be rather difficult in that if you have something that's very popular
|and very large and very high quality, it can become very expensive to distribute it.
|It becomes expensive to be popular. With broadcast over the airwaves this doesn't happen,
|You're screaming loud enough, everybody can hear you - not a problem.
|On the internet it's a huge problem so BitTorrent was based
|on this very fundamental calculation of well if you're sending out something,
|and everyone wants the same thing, they can just send it to each other,
|So there's this logistical problem of how to make that happen,
|so I figured out how to make it happen.
|Well the basic problem is a pretty simple one,
|there's plenty of upload capacity out there not being used how do we use it?
|So that's a trivial calculation on its own the problem is,
|these are what you call low quality resources.
|They're peers, they're untrusted, they are of unknown potential transfer rate
|they're not of terribly good transfer rate to begin with and they're not very coordinated.
|This isn't really so much of a problem of make something that works,
|so much as make something that works reliably,
|that can handle the fact that peers just sort of disappear and never come back again.
|When I started working on it there was a bunch of people working on very much the same thing.
|I decided on an approach that was actually much, much more ambitious
|than a lot of the things that had been successful up until that time.
|In that you when you're distributing something on the internet,
|if you're doing it via HTTP, you kinda don't want everyone
|to come and download the same thing at the same time.
|You want nice small things that are distributed around when people download them.
|and this is good for making it so you don't have too much load on the one central server,
|and I went and did this calculation and figured, well no, I want to do the exact opposite thing.
|I want everyone downloading the same thing at the same time.
|Because if, and this at the time this was a pretty big if, if you can get a handle
|on all the difficult logistical problems of making it actually happen,
|then you can make it so that the initial place only has to upload one copy
|of the whole thing and everything else will be distributed between peers
|and you actually get maximum efficiency in the very situation you were trying to avoid
|when you were doing everything via HTTP.
|So in that sense I was being rather ambitious although other people were working on the same problem.
|The difference was in terms of approach, that I came up with an architecture
|which was designed first around reliability and efficiency
|- in fact only reliability and efficiency- it's an utterly bizarre architecture
|unless you consider it from the point of view of ok...
|first thing, let's just assume that peers are unreliable
|that we don't know what transfer rates are
|that peers are untrusted and tend to go away
|and then, out of what's left, how do we make something work
|other people were trying the tree-based architectures, which proved not to work
|but the reasons why are very much centered around reliability,
|and are not obvious unless you've done some networking and know that just...
|peers go away and never come back
|DRM has a lot of political momentum right now
|it's just like if you're putting content up online you have to have DRM and...
|whether this is psychological, whether technicals are saying it,
|whether lawyers are saying it, whether just collectively everybody feels
|that somebody must be saying it, so you have to speak in one voice demanding it...
|... is a little unclear, and varies from place to place
|When you go to the movie theatre you pay
|when you get a DVD you pay, when you rent a DVD you pay
|there are a few things going on
|one of the big things is what people associate with their home experience is watching television
|You turn on the television and then you watch,
|and people are rather disinclined
|in some ways
|paying for something to watch at home
|they want to just have ads and watch it
|by analogy with television
|another thing that happens is that people are leery
|frequently leery of paying for anything online
|just putting in a credit card number,
|because credit cards are so fundamentally insecure
|makes people very nervous, they don't want to do that,
|and it's an annoying process entering in your credit card number.
|Now the ridiculous insecurity of credit card numbers has a lot to do with
|with the ridiculous way banks work in the United States
|where things are big and bloated and poorly done technologically
|and there's very little if any incentive to fix it.
|I would say that people are a little used to now,
|when they download videos from the net, not paying for it,
|it's just what they've been doing,
|the paying for it model just hasn't been there!
|So people just habitually aren't very used to paying for things.
|At a certain point when you get down to what's termed level of cost
|the actual price being charged is de minimis,
|whether that's a dollar, or ten cents or one cent.
|it's a little hard to say.
|But at some point the actual price paid ceases to be a concern.
|and that's for extremely popular content
|isn't very de minimis
|when you multiply it over the number of people who are paying it
|that's effectively what advertising online winds up being
|the monetization on it is small.
|Generally speaking a penny per impression,
|but winds up adding up in the end.
|The question there is what is the form of that monetization?
|Is it via advertising, which people are implicitly paying for in some way,
|Is it explicitly paying where there is this usability issue of making the payment,
|and the concern about fraudulent charges happening when this payment is happening
|concerns about incentivizing spam, bladibladibla...
|So at a certain level
|there's the cost of the distribution and there's the value gotten from the thing
|and if the cost
|is some very small fraction of the value gotten from the thing
|people cease to pay any attention to it whatsoever!
|And the question then becomes what is the form of the payment.
|Advertising is certainly a compelling model
|in that it's very very simple,
|Whenever you have payment going through a distributor
|there's the whole issue of making the payment happen
|both in terms of authorizing charges and redistributing the money
|and it has to somehow hook into the payment system,
|and advertising is somewhat inefficient
|in that it implicitly hooks into the payment system
|via some complicated route of people watching the advertising
|doing something eventually, somewhere out there,
|But it's much much simpler in general,
|a more straightforward way of doing things.