American investors love companies that have growth potential but may be losing money: Amazon, Pandora, etc. Is Spotify next?

[youtube http://www.youtube.com/watch?v=Z8AcNDkxPXU&w=600&h=315]

Amazon doesn't really make profits, and investors love it. Pandora is having strong growth in monthly active users, but was a company in 2005 and just had a profitable year in 2013 -- and that's only if you remove certain one-off expenses. Meanwhile, look at their stock:

Now, Spotify and Pan…