Isaac Asimov

It is change, continuing change, inevitable change, that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be.

Hammer down product fundamentals first. Make sure you've got something that works before doubling down on promotion and marketing. Create a groundswell of organic support, and only then leverage PR and advertising to spread the word.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.