Very interesting, this doesn't match my experience, can you say more about how you reason to the claim that Google created a separate 'infrastructure business entity' ?
The only way the business model of selling spare resources could work is if you found customers with a different usage pattern to fill the trough. That's hard.
Yes, you can find some customers with time-insensitive batch processing that could be done during the night time. But Google and Amazon already do massive amounts of batch processing, and still won't have a flat utilization level over the day.
Or alternatively you could try to flatten out the diurnal variations by making sure there's no geographic affinity between users and the DCs. But that's suboptimal given intercontinental network latencies.
The Great Recession hit, Google stopped building infrastructure for a time and focused on utilization, which lead to some awesome improvements in cgroups and i/o scheduling and such, and only after that and some early successes of both AppEngine and other projects which were kind of like it but much less well publicized, did the idea start to be considered as something Google might actually productize.
I could completely see them building infrastructure at this stage which is purely for rent, they have the recipe for building data centers pretty well baked. But I have never heard it put that they started out with that in mind.
> Thinking at Google has changed since you left.