A while ago, I signed up to Memolane, which sends me lots of emails, a few of which I read, telling me about what I tweeted about (or posted on Facebook or Flickr) on that day X years ago.

That's not going to happen any more; recently, they announced that they had been bought up by another company, and would be shutting their service down and deleting all their user data.

But slightly less recently, it reminded me that it is four years since I tweeted about boxing up all of my music and 'temporarily' put it into storage in my parents' garage.

My Dead CDs

Four years ago, the second bedroom in our flat changed from being 'my other room' (full of computer and music gear) into being a nursery, in preparation for our first baby. So my CDs were – reluctantly – boxed up and moved into my parents garage, until we could clear out some space to put them in the living room.

I say 'reluctantly' - kicking and screaming might be a little closer to the truth. I was very attached to my CDs, with my music collection being a central part of my life for… well, for most of it.

Four years on, we now have 2 children, our small 2 bedroom flat in London has been upgraded to a 3 bedroom house in Hertfordshire with more than enough storage space, and yet those boxes of CDs are still sitting there.

I do plan to move them, if only to free up some space for my dad – but I can't see myself moving them anywhere other than into my own attic space where they will sit equally ignored and forgotten. I still have a sentimental attachment to them, so I can't see myself selling them off or giving them away. (I like the idea that one day I will dig them out for my own kids to go through, where they will probably view them as odd historical artefacts from a past age and wonder if they are old enough to become valuable.)

But the thing is, I don't miss them at all. In fact, until a few days ago I had kind of assumed that the cupboard underneath my TV had a few dozen CDs in it. Actually, it turned out, it has a load of DVDs in it, and a few PC games. (I haven't owned a PC for about three years now…)

The only CDs that have any real place in my life today are the 6 CDs that have been sitting in the multi-disc changer in my car since last July. (Usually, I put music from my iPhone on in the car; the CDs are a fallback for when I can't be bothered to plug it in.) Now, they are simply the containers that my music comes in, about as much use as the box that my last pair of shoes came in. I do still mostly buy CDs (as opposed to digital downloads), but I'm not quite sure how much of this is a genuine affection for the physical medium and how much is a combination of sentimental habit.

So, the transition from physical to digital music for me has been quite linear; I built a digital copy of my library, and I started adding to it. At that point, my "collection" became the digital version, rather than the physical "originals". Every CD I buy gets ripped to a digital format; I can't think of any music I downloaded that I have then burnt to CD. But the weird thing is that if it weren't for the particular timing of house moves and children arriving, I'm not sure I would have noticed the transition.

Now, my collection also lives in "the cloud" (specifically, iCloud.) Most of my listening happens on the iPhone (or iPad), so iTunes Match is the easiest way of getting songs onto it. Already, the digital copy of hundreds of CDs (weeks worth of music) on my laptop hard drive has become too big and inconvenient to be my 'living' music collection.

The Death of Physical Media

The story of the difficult transition of print media from physical to digital is pretty well understood by now; readers like digital newspapers and magazines, they don't like paying for them quite so much, and publishers are struggling to readjust their business models to compensate. But print media isn't 'collectible' in the same way; other than habit, buying newspapers every day doesn't give you a reason to buy a newspaper the next day. It's easy to stop buying print issues and feel like you have as much of an idea of what is going on in the world. (And if you're used to the feeling of today's papers being filled with yesterday's tweets, you might feel like the opposite is true.)

Recently, Enders Analysis published a report on the 'death of physical media' (subscription required), which talks about the true nature of the shift from physical to digital media for the music and film industries. It points out that the real danger to the industries is that when they make the transition from physical to digital products, many customers (particularly the older ones who spend the most money on music and films) won't migrate over to making digital purchases; they will simply stop buying the products.

For me, migrating my own music collection to digital was reasonably straightforward. I moved house, arranged my CDs on a set of shelves, and (with literally one or two exceptions), didn't touch any of them again for a year. All of the music now lived in my iTunes library, which itself had moved (slowly and painfully, one ripped disc at a time), to a computer – and then quickly and easily from one computer to another. Today, although it still sits on my laptop's hard drive, it 'lives' mainly in the cloud – an annual cost of £20 or so means that I can access them all from my iPhone, iPad or Apple TV, from wherever I happen to be when I want to listen to something.

And yet… I still tend to buy new music on CD – mainly because I don't usually buy brand new releases, and a CD on Amazon tends to be a little cheaper than the same album on iTunes. I like being able to easily put them in the car, or know I can take them/lend them/share them/play them elsewhere. So one CD has obvious benefits for me over a purely digital download. But a couple of hundred CDs – what used to be the first thing I would unpack in a new house, and would spend hours organising and arranging – is now just a waste of space.

Is my DVD collection next?

For DVDs, the transition from physical to 'pure' digital is a bit less straightforward. Ripping a CD is easy - a typical computer's CD player will pull an entire album in just a couple of minutes, separate the tracks out, and also look up the artist, album and track titles from the Gracenote database. A CD album typically contains about 600MB of audio data, which when compressed to something like MP3 or AAC format will take up about 250MB of hard drive space. A typical film on DVD will be about seven times as much (7GB or so), so ripping a DVD takes longer and uses considerably more hard drive space. It's not hard - it's just a little more time consuming.

But you probably don't just want a DVD image file on your computer (which is what ripping software will usually make for you) – you want it in format that will play on your computer, your smartphone, your tablet, your PlayStation/XBox/Apple TV or whatever else is connected to your computer. You probably won't want all of the foreign language subtitles or alternative audio tracks, or the extra features, fancy menus etc. (If you're storing them on something with limited space – like a phone or tablet – you will want to squash the file size as much as possible, so that you can store more videos in the same space.)

Basically, you will probably want to make a simple video file out of the DVD. That takes a fair bit longer – depending on how powerful your computer, probably upwards of an hour (and being a CPU intensive task, unlike ripping CDs it isn't something you will want to do in the background while you are busy using your computer for other stuff. Apart from anything else, it makes laptops run hot with the fans spinning on full – probably not something you want sitting on your legs…) But if this is a digital replacement for the DVD (ie. so that you can box up the DVD and forget about it) then you will want a high resolution, low compression version for playing on a TV, but a lower resolution and more compressed version for a phone or tablet (where screens are smaler, and storage space is more scarce.)

For me, ripping a few hundred CDs took a week or so of constantly swapping out discs while doing other stuff with my computer. Ripping a few dozen DVDs would probably be something I would do over the course of a few months, doing one or two an evening when I wasn't doing anything else with the computer.

So, while it would be easy enough to just start buying new films in a digital format, it means having a digital and physical library sitting side by side for quite a long time. It also means that doing what I currentlt do with music (buying CDs, ripping them and then putting them away, probably never to be touched again) is vastly more inconvenient to do with DVDs. Whats more, there will probably never be an 'iTunes Match for Films and TV' – the industries just don't want to embrace the idea, few people have the problems that a digital video library create, and right now, streaming a film over a mobile network is just too bandwidth-intensive to be a regular day-to-day activity for most people.

And that isn't even touching on the legistaltive issues; the fact that its illegal to rip DVDs, thanks to the DCMA/ECD – basically, while copying media that you own for personal use or certain other protected uses (eg. commentary, academic etc.) is legally allowed, it isnt legally allowed to circumvent copy protection. (Note- IANAL, TINLA etc.)

Compared to spending (probably) nothing but a few evenings to rip your CDs – a one-off investment of time that ought to last forever, for music that you will probably listen to again and again (compared to films that you might watch a handful of times if you really enjoy them.)

So, while I can imagine CDs being phased out from mainstream usage in the space of a few years, I find it much harder to imagine most people seeing the appeal of moving to a purely digital video collection. (Let alone the industry moving into one of cloud-based libraries and digital lockers.)

Will books live on?

There is an idea that technology is aging in reverse - the longer a technology lasts, the longer its remaining lifespan should be expected to be. So with the technology of the book dating back something like 2,000 years, it should make sense to expect it to outlive the likes of CDs, DVDs, MP3s etc.

Personally, I really like books. I like carrying them around, ready to be read. I like the fact that you can see what someone is reading – meaning that you can identify if someone you know is reading something you've enjoyed (or expect to enjoy.) Try that with a Kindle, or with music when someone has a pair of headphones on…

I like them as furniture, showing visitors (and reminding myself) that they are important to be. I like being able to borrow or lend them, or skim through to find a particular passage. I like to look through the shelves of a bookshop. (Unfortunately, I'm less good at making time in my life to read them; I now buy more books than I read, which is the kind of thing I found incomprehensible a few years ago.)

But probably more importantly, eBooks just don't work as well. Carrying a book means I have something to read; carrying an ebook reader means I have lots of things to read. Given that I have Facebook, Twitter, an RSS reader, email, Instapaper, magazine subscriptions (some of which also live on my iPad) and, you know, the rest of the internet… I'm not short of things to read. The only time I can think of when I felt genuinely frustrated by not having something to read is when finishing a book in a series and not having the sequel to hand straight away.

So, having a book means that I'm more likely to read that book– the choice presented to me being effectively "read a book or something else" – as opposed to "reading, listening, watching, playing, writing, organising etc. etc. etc."

This is a bigger difference than it might sound at first glance. What it has meant to me is that carrying around a book versus an eBook is the difference between reading it and wanting to read it (or reading a chapter or two before getting distracted.) I find it really hard to see what it is about eBooks that is actually a tangible benefit for me.

So… Where is this all heading?

Physical media will not die. We will never live in a purely screens-and-speakers based media world. While music and newspapers are moving into a digital world, films and books are simply being augmented by their digital counterparts.

Now, this might well change. If more people are watching video on screens other than TV, then maybe we will start seeing content designed for different devices – and different ways of collecting and curating video content. (This is an area that YouTube clearly want to be playing in - while they are happy to offer online playlists and 'watch it later' lists, they appear to have no interest in offering a service to let you download video to watch offline on your phones.)

But the other thing to bear in mind about anything 'in decline' – if there is less of it, then what survives becomes more valuable. If we spend less time talking face to face and more time talking online, then the limited face-to-face time becomes more valuable. In a world where we collect more digital and less physical media, the physical becomes more special. (Instead of shelves of hundreds of CDs, I now have a few dozen of my absolute favourites - and a couple of my absolute favourites on vinyl - despite the fact that I don't own a record player at the moment.) The job that I want my physical music to do is no longer 'hold my music' - its now furniture, a statement about my tastes; something closer to the band posters and t-shirts that I used to collect as a teenager.

The major caveat is what happens to my kids things. Right now, I need their video to be on DVD - so that they can put htem on themselves, without having to worry about the right device and lsoftware and logins etc. I need it to play on the portable player in the car, just as much as the main living room TV. At some point, as they grow up, their collections will become their own.

Or will they? Why would they buy a film, in a world where you can rent it for a fraction of the cost and watch it instantly? Why would they buy an hour or so of music on a CD, when for the same price they could access unlimited streaming music for a month?

The big question for me was why my next film or album purchase would be digital. The big question for them is why their first film or album purchase will happen at all.