Most of the time , like many here i like to have the original artefact.
Now ,to be able to listen to many things BEFORE you buy it- or no- is also great.
I have an HUDGE collection . Few thousands LPs and few thousands cds.
But i still enjoy getting from Emusic some albums i have on LP. Like it i can take it with me .
Yes ,it is not lossless , but i do not think you use to take your stereo system with you when going out.
And a mp3 Lame 192 VRB sounds better than a cassette in a walkman.
As well i can share it. I do not mean on p2p ,but with friends.
Also ,frankly some albums ,to have it in a good losy format is enought. I would never ever buy them ,even for cheap.
The same ,to be able to listen to unknow music , even in MP3 is great. Some you delete them ,some you keep them -but mp3 is enought- ,some you buy it.
I do the same when i get cds from friends. I rip all to lossless format.
Latter ,when listening to it ,or i delete ,or i keep in lossless ,or i convert to OGG.
And, a few ,i buy it , even if i have it in lossless format on my computer.