I think PostgreSQL does benefit from Amazon RDS and Google Cloud SQL indirectly. Unlike MongoDB, it is a real volunteer-led open-source projects, and the goal

I think PostgreSQL does benefit from Amazon RDS and Google Cloud SQL indirectly. Unlike MongoDB, it is a real volunteer-led open-source projects, and the goal is to provide an excellent database to users rather than make money. Having easy-to-use cloud hosted versions available helps with attracting users, mindshare, and perhaps in the long run developers to the project itself. Having cloud hosted versions from big vendors means that it's easy to justify "we'll use PostgreSQL for this project" to management or clients.