The thing about marketing is it can at best get people to check your product out. It can't make them keep using it.

That's why I didn't mention it, it's boring table-stakes stuff. Obviously if you don't tell anyone about your product, no one will use it. That's not the hard part.

The hard part is of course making a compelling enough product that people actively want to use it. The really good products even advertise themselves to a certain extent.