why to pay to listen music online?

resontly i notice some of my friends uses software that links to online music data base like , KKbox. It is basicly a software that is link to the company's server, which provide the newest music; while the user can create their own play list and listening to their favourite tracks online. what surprises me is how the interface of the software, actually gives out the subtitle for the tracks simutainously while the track are playing; like an karaoke. I know it isn't a new innovation, but it actually uses a function that might require plugins for other music playing softwares; and increase the visual pleasure to the song( with surporting subtitle and the album's cover displaying when ever a song is playing.) The only down side is the software is membership based, as the monthly fees apply. But by using the software, it means getting the newest tracks, while listening to it with a interface offers lots more fuction than your ordinary player; and also lligal. But for NZ's limited bits usage, do you guys think it is really worth it? do you think its gona change the way of how many of us still just downloaded our favourite tracks, when we can listen to it tho a paid provider?