Is Salesforce.com 100x as efficient as Amazon?

The Efficient Cloud: All Of Salesforce Runs On Only 1,000 Servers

The raw numbers in this article are pretty interesting:

Salesforce talked about its own back-end infrastructure and revealed that all of Salesforce.com runs on only about 1,000 servers. And that is mirrored, so it is really only 500. Think about that for a minute. Salesforce has more than 55,000 enterprise customers, 1.5 million individual subscribers, 30 million lines of third-party code, and hundreds of terabytes of data all running on 1,000 machines. Amazon's Web Services, in comparison, runs on about 100,000 machines I am told by someone with knowledge of Amazon's server infrastructure.

But I'm a little confused about how he takes those and jumps to the conclusion he leads the story with, that salesforce is 100x as efficient as AWS:

But still, that is roughly a 100 to 1 efficiency advantage that Salesforce has over Amazon's cloud.

In order to make that calculation, it sounds like he's assuming that Salesforce does 1-to-1 the amount of actual work (processing, transfer, etc) as all of amazon's services do. Thats a pretty remarkable proposition to make, and to hinge your entire article on, without providing any numbers to back it up.