A more useful mental model is "your website will only get the traffic you drive to it." Substitute app, software, tool, etc. for "website" if necessary.

But this makes the reality more clear: building it is not enough. You must take active, focused marketing action to build an audience or customer base.

That doesn't have to mean running ads, although I would not rule out ads. It can include PR, SEO, events, social media, etc. The point is that if you want a product to succeed, you have to be ready to spend time and money to make it succeed.

Now, it's true that a few special products are so awesome that they take off on their own. But most products don't. And if you happen to build one that does, it certainly won't be hurt by some marketing.

I believe the movie Field of Dreams existing had the single most detrimental effect amongst app developers and executive producers than any other movie, because they keep thinking if only they build a good app, then the audience will come to them. NOT TRUE.