We can think of a tech product as a sum of smaller products with a common core product. Github is a graphical interface for Git, embellished by a social network of developers, a static web hosting service, tools for Continuous Integration...
A tech product is not atomic, it's a molecule of features. A country with a capital city, secondary cities, towns, and inhabitants.
Building a successful product is probably a lot like building a successful country, except you don't dwell on petty politics.
You want people to love your country so that they can settle down and help you grow it. That's user acquisition and user retention.
More importantly, you must build your cities so that they can complement each other. It's especially important for indie makers to understand. When Pieter Levels built Nomad List, he augmented it with Hoodmaps and Remote OK - three atomic products reinforcing each other in the Nomad niche/country. Marc Köhlbrugge did the same with his Maker country: WIP, Startup Jobs, and BetaList.
Focus on one core product, build satellite products for increased synergy. Never forget the people are sovereign: they are the ones who make or break a product. As a founder, lead the way to sustainability by eating your own dog food.