Snap and Spotify account for 13.7% of Google Cloud: https://www.cnbc.com/2018/03/20/spotify-will-spend-nearly-45...
Snap also has a huge contract with AWS, for what it's worth. Other large customers like Apple also split their ticket between Amazon and Google.
I would argue on many points GCE is clearly significantly superior to EC2.
The Google billing model is far better, they bill on straight CPU and Memory, which you can combine in any desired ratio. Amazon has well over 100 different instance types.
Google gives you an automatic sustained usage discount. Amazon requires you to commit to reserved instances up front for 1 year minimum, and those have to be specific instance types, so as your workloads change you can't reallocate capacity.
GCE has workload live-migration. If the underlying hardware that your VM is hosted on begins to fail, they will migrate you to new hardware in REAL TIME without any downtime other than a sub-second pause in processing.
Amazon will notify you that your hardware is failing and give you a deadline usually a week or so out to reboot your VM, if you don't they just terminate it.
I could continue for several more points if interested.