and the number one most streamed song on spotify this year, "happy" by pharrell ♪ because i'm happy >> reporter: spotify investors appear happy for now. despite its losses the company is valued around $4 billion with reported revenue of over $1 billion. and an ipo could come soon. but there are big issues spotify just can't shake off. taylor swift's pulled all of her songs from spotify complaining that it's not paying artists enough. ♪ ♪ >> reporter: spotify's hoping they do get back together. as it tries to keep investors happy, spotify can't afford more ex-lovers or blank spaces. >> i've got a blank space, baby.