iPod Day is celebrated every year on the anniversary of the first release of the iPod on October 23 2001.
Back in 2001, portable music players were still mostly cassette walkmans and portable CD players.
Having music on flash memory was quite a novelty back then.
Also the iPods were pretty and in Apple tradition advertised religiously.
The first iPod had an impressive storage of 5GB and was $399.
So, actually….it took some years for it to catch on because of it’s price and of course it only worked with Apple products, because compatibility was not on the priority list.