MasterBlaster84 said:
Proprietary encoding (ATRAC) would be one good reason, on most MiniDisc machines you didn't even have the option for other formats. At least Apple gave the ipod the ability to play MP3's, Sony should have done the same .
I have to disagree here, the problem was the interfaces (itunes vs sonic stage) & fixed storage vs removable media. Mini disc started to really suffer when the 20/30gig classic iPods came out because nobody wanted to purchase multiple discs anymore, even know it was a better more flexible format. The cost of new recordable media types are high for the first couple of years due to having a royalty fee attached, when High-MD was released it was around $25AUD per disc compared to a spindle of CD-R for the same price, this turned some average consumers away.
Sonic stage

the check in check out on Net-MD players caused some issues. The recordists out there know that you should have been able to transfer any of your own recordings back through the PC but sonic stage didn't allow this. I recorded a number of live gigs and had no real way to export them without doing a real time transfer to another device. Sonic stage was also full of DRM crap
The user interface and indexing of sonic stage was not as good or intuitive as itunes.
Sony being Sony and selling the technology then releasing new players with updated version over their competitors (Net MD & LP as examples) Sony also suffers on new formats because consumers are scared that if it doesn't work out for Sony they will totally abandon it and leave them end buyer high and dry
Lack of prerecorded material in some markets. In Oz we didn't have access to prerecorded discs and this did have a small impact, not much but some.
Fashion, iPod was the must have fashion accessory at the time (think beats now) and as such all other players suffered sales losses.
There was some areas of the market that the MD really took off in, think of journalists and live music fans, no other device (except cassette in all forms) offered what MD could in these areas.
This is what I noted when MD stopped selling, at the time I was in sales at one of Australia's biggest AVIT retailers