This is what I wrote in the box marked 'other' for why I was cancelling my spotify account.
I love the Spotify desktop application and the iPhone app works just fine for listening to music. However, as a busy professional, the only time I have to search for new music and/or make playlists is while I am on buses, trains or planes; at which time I have my iPad not my PC.
I got excited toward the end of last year when you said an iPad app is coming soon. I decided to wait it out and thought that finally yesterday you would have listened to your customers and release an iPad app. You can imagine my disappointment when you announced a partnership with a unhealthy sugary drink company that I don't even like. I have yet to figure out why I should possibly care about this.
I'm not delusional enough to tell you how to do business, but I will be taking mine elsewhere.
[Update: Spotify released an iPad app. It's good. Rdio got crashy. I'm back to Spotify.]