[bradleysmith]

This makes the most sense to me as motivation for this kind of give-away. Both familiarity to soon-to-be-promoted techs, as you said, and establish themselves as the system to migrate AWAY FROM.

To have the first $100k of server time's code written on their platform is not meaningless. Perhaps I'm a sub-par wizard, but host migrations are a very real pain point in my experience. With $100K's worth of time spent developing on Google's platform, that pain would be pretty well developed by the time a startup would get around to worrying about it.