iTunes tracks residual value; BIG FAT ZERO

I find this really funny, and in fact I'm quite smug about it. I read earlier today on Twitter that a guy I'm following was wondering "...what to do with all my purchased iTunes tracks now I'm using Spotify premium...".
HAHAHAHAAH! Let me laugh for a bit here. HAHAHAHAHA. HOHOHOH!!
Right, composure...
Here's the deal; You can burn them to DVDs and/or data CDs. Even Audio CDs. Then you can stick them in a box in the loft. That's it. You can't sell them because that's illegal, even if someone would be prepared to pay for your second hand digital music.
Feel a bit f'd over...?! Well you should be, all of you iTunes customers that haven't thought about "what's next". Sure, iTunes (and other digital music download shops) are fine if all you want to do is to listen to the music. And the word listen really is crucial here.
Let's compare to that "old' format", the CD Audio disk. With a CD you can give to your friend to listen to. Yeah, you can go to the pub or café to meet your friend, hand them a CD and it's pretty sure they can listen to it at home. You can get the CD sleeve whilst listening to the CD in the player, and you can look at photos and read the stuff in there, such as lyrics. You can do this anywhere in the house, even outside. You don't need a daylight readable screen for it. And you know what. You can give this CD sleeve to your 150 year old grandmother, and she'll be pretty compatible with it.
Another cool thing is that, should you meet the artists on the CD you can get them to sign the CD (and increase the CD's value). Novel concept; Sign my MP3 files (or AAC in iTunes speak).
But here's a part you didn't think of; You can actually sell your CD onwards. The residual value of a CD might not be much (unless it's a collectible), but there definitely is a residual value. Your digital music files don't have any residual value. Nada. Zip. Zilch. Big Fat Zero.
So, now that you're aware of this, you can either keep buying your inferior digital music files, or you can start buying physical formats that, not only sound better, but are actually tangible in more than one way.
Oh, and Spotify, another "music leasing" idea that's not to my taste. I'll leave that to another caffeine fuelled morning.
PS, sorry for the quetness, been busy and boring.