Yes and no. Yes, if you do good work/make a good product/run a good service and its fairly priced, it's more likely to do well than if your work is terrible. I

Yes and no. Yes, if you do good work/make a good product/run a good service and its fairly priced, it's more likely to do well than if your work is terrible. It'll usually be a million times harder to promote a terrible business than a good one, for obvious reasons. But also no, because 'build it and they'll come' hasn't worked as a marketing strategy for... maybe thousands of years. If people don't know you exist, they won't become customers, and since most customers won't promote even a good business or service to other people, relying on word of mouth is unreliable at best, suicidal at worst.