You can bet your bottom dollar Spotify are getting heavy, heavy discounts. Google are ramping up here in Stockholm, partly to get this account. This has been in the works since before last summer, so they've taken time before announcing it.
The precedent for Spotify was switching from Cloudera to Hortonworks a couple of years ago. Rumours are that they got their licenses for close to nothing from Hortonworks, they were so desparate to close them. Same rumours going around vis-a-vi GCE...