You're buying nothing.
Yes, you're buying music, or video, or whatever. "Content". But ultimately it's just data. You hand over real money* and get some data.
To turn it into "something" you have to burn it to a CD. To make it really something you'll burn it on a good quality CDr and make a cover for it. The cost of which will certainly undo any benefit (discount) from buying it online.
Further, in any of the current implementations of digital music stores, you have to buy music with your own account and own credit card. You cannot buy music for someone else. Burning the music to CD might be allowed (or might not be) but giving that CD to someone else is illegal. Piracy. You go to hell and you die.
Ignoring the fact that such technical achievements (downloading and installing iTunes, registering an account, buying some music, burning that music to a CD) are complicated, difficult and ultimately beyond the reach of most non-technical people.
So I couldn't expect digital music for Christmas. Nor could I buy it for someone else. Doing so would feel like buying someone a burnt CDr or a photocopy of a book. It'd feel... dirty. Like you haven't actually bought them anything. You've just spent money on their gift.
You can get a gift card (voucher) for iTunes or Destra music or Amazon MP3 or whatever. You can even buy them in real stores. But that's a voucher. You may as well give someone money.
The closest comparison I can come up with is buying someone a voucher to a service, like a massage or day-spa. These aren't bad gifts, but they're not "things".
Worse, when you buy digital music for someone by buying, then burning to a CD, it's like you bought a massage for someone then enjoyed it yourself... Digital music can't be unbought. It can't be returned. It can't be on-sold. It's a used-up service.
This is the best demonstration of why commentators suggest digital music "cheapens" the product. Digital music isn't a "thing" anymore, it just "is". It's a service. Something that's gone once the money is spent.
It turns it into nothing.
* OK, I'll be the first to admit that the majority of purchases these days are done either on credit or EFTPOS which is not actually "real" money in the same way digital music isn't "real" music.
** I feel I should note that just because something isn't a "thing", it doesn't make it a bad gift. Depending on what that "not a thing" is... which is my point. Point!