Why would they use something that's similar to Spotify when they could use Spotify? The number of times I'm on someone else's computer and go "Oh, I'd really like to listen to some super obscure track not already on my MP3 player/smartphone/Kindle/what-have-you" are virtually nil, and competitors lack the huge selection of music that Spotify has.

It's not really similar at all. This is just another web radio service, whereas on Spotify you can listen whatever you want. Also, the UI is horrendous.

That's not correct. We7 isn't just another web radio service. It absolutely is a service where you can listen to whatever you want, with a fairly decent selection of (major label) tracks. The major advantage over Spotify up until now has been the fact that it has a web interface, although I do take your point that the UI is pretty horrendous.