I don't know the details in the case of this particular article, but for reference we have ~60 machines on EC2, a couple dozen of TB of data on S3, we do around

I don't know the details in the case of this particular article, but for reference we have ~60 machines on EC2, a couple dozen of TB of data on S3, we do around ~250MB/s and when picking our CDN both cdnetworks and akamai (which we ended up going with) worked out a lot cheaper than cloudfront.