If you start from scratch, you might want to start with a community. Not BUILDING a community, but participating in a community. The more specific you can get, the better. For example, if I were to build a business for developers, I'd dive deep into the community if "Elixir developers using Phoenix to build low-touch SaaS products." That's my niche, that's what I do, that's what I care about most.

Finding that initial target audience and committing to it is the key. Embedding yourself in their communities is the way you can

• build a reputation as a community contributor (which will cause people to pay attention)
• learn about your peers' day-to-day challenges (which will allow you to find and rank their critical problems)
• find people to talk to about your solution ideas to their problems (which will allow you to quickly (in)validate your product ideas)
• determine how and where people already spend their money (which will suggest how much they care about solutions to their problems)

If you're not experiencing this first-hand within a community, everything you do will be based on pure speculation.

I've written at length about this in The Embedded Entrepreneur, but here is the gist of how you can build that audience from nothing:

• Engage with people where they already are. If you help them, support them, cheer them on, you'll establish a relationship with them. You'll become a trusted and respected peer because you trust them and respect them. Don't yell your "content" into the void. Help real people with their real problems. One by one. This doesn't need to scale. It'll compound over time.
• Empower people. Share their pleas for help with your own audience. Celebrate their victories, and commisserate their failures. Loop in people you know into conversations where they could help out. Become a connector. Have you ever noticed how people with great reputation seem to know everyone and are known by everyone, too? Become that person.
• Trust that this takes some time to be effective. You won't create a huge following overnight. People will trickle in initially, one by one. Consider this: you don't get 5000 followers. You get one follower, 5000 times.

Over time, you'll build an audience that becomes more and more interesting to observe. People talk about their problems all the time: they complain, they ask for help, suggestions, or alternatives. Listen to your audience to find opportunities.

Once you have isolated an opportunity, conceptualize a solution and constantly talk to the people who feel that pain. Learn more about how they solve their problem right now, and what they struggle with.

Also, read The Mom Test to avoid asking self-serving questions. There is a time to ask people to give you their opinion about your product, but the discovery stage is not that time. What you need for your own validation efforts — before you build anything — is a clear understanding of the problem and the people who have it.

Use your conversations around the problem as an opportunity to involve people in your business-building efforts. As a trusted community contributor, you won't come off as a salesman, but as "one of us" who is trying to improve the lives of the community members. Consider building your business in public, right in front of your peers. Their involvement will make it much easier to find initial prospective customers who can (and will) give you their honest feedback on your product.

Trust begets trust.