There is a thing called big data and small data and you gather these type of demographic information from research on competition, neighborhood demographics, lifestyle, family routines in and out of a home, sometimes jargon and slang can be key identifiers of niche groups, there is no single way of doing this but you do need to have a process in place that you can track your own work and see yourself getting to small demo each time. Look into Blue Ocean strategy practices, at Unthink, we use this to create campaigns for our clients even if we don't achieve blue ocean we get off the beaten path typically used by competitors and this has helped us achieve competitive advantage for our clients.

Been there many times. I didn't always get it right. But practices can lead to better results. Much better results.

Short answer: Three questions you should answer for yourself first: 1) What markets are you a member? 2) Do you have enough expertise to be a "big fish" in that market's "small lake?" 3) Is that target market big enough to support me if I succeed?

That last one maybe should be answered first! {grin}

The most effective marketing tool I know for choosing markets is the "Lean Canvas" by Ash Maurya. I would love to introduce you to this tool. It will change your trajectory through business and life. IMNSHO

Schedule some time for a call. A short tour will save you hours of wasted effort trying to figure it out for yourself. Ask me about "Avoiding the Left Turn."

In 2008, when the world was going crazy, understanding our market and asking the right questions first, helped me take a business from PBT of 480 million to 1.3 billion (one of Barclay's acquisitions).

The thing to do first I find is not to focus on the answers, but on some very simpile questions, which will drive complexity soon enough. This is true of B2C or B2B, and we will build on this with the traditonal strategic methodologies.

1) what is your business great at? without even thinking of your competition yet, what can your business do exceptionally well?

2) now, what can you do better, cheaper, quicker, newer, sexier (whatever it is) ...so that you stand out from the competition, uniquely? as a mental aid, if I was to google your business, what combination of words would get you top of the ranking, consistently? think of this Volvo is a car, but it owns the word safety. what words must you own or do you own?

3) what defines the different types of customers in the market you want to serve and dominate? what are the characteristics that define the segments of the market?

4) what is the reason that customers will want to use your product or service? what problem are you solving? how are you making their lives easier, better, whatever (avoid competing on price, niche markets obviously exclude this!)

5) next you have to understand your position in the competitve landscape, what external forces will you have to deal with? New tech, New Regulations, New Entrants, Powerful Encumbants, Easy substitutes etc?

6) now you need to go back and check, and really understand. How will you make money? this is an easy question with a non trivial answer. ask your colleagues these two simple questions. 1) if you invest a single dollar into the business, what will it be turned into when it goes through the economic engine, and finally reconverted into cash in the hand? and VERY IMPORTANTLY, how long will that single dollar be tied up within the business before it is converted into cash again?

Now you may think this is stupid, but it always gets ignored. Would you prefer to have a dollar turned into $1.50 over the course of a year, or would you rather have a business where a dollar, gets turned into a mere $1.10, however it only takes a month? Do you see how the same $ can be reused 12 times? This is a compound effect.

I have all of this explained on my website, with everything you need to answer your questions. It's free, and once you have some concrete thoughts, I can help you if you wish. This is the site: http://www.spark-sme-services.co.za/ navigate to the toolset, and chose the relevant sections. I would suggest Strategy, and Value Management first. In here you will find tutorials, worked exmaples and key questions?

There's a lot more to it, but this will get you started off, the site will help and I willm help you fill in the gaps if you need.

Good luck
Ivan

I could propose some solutions or tools.

When you refer to "a niche market for a dentist in a specific area", I assume you mean a local area – a city or a state. But tell me first whether you're working for a single client or a succession of such clients. In one area for all clients or in multiple regions?

First develop a Value Proposition Canvas. Identify at least 25 pains and 25 gains associated with the customers. Here is the catch. Different sub segments of your target customers would have different pains and gains. Using these pain-gain sets, you can identify promising and niche sub-segments and develop a completely customized solution for them.
Ex: 1)People who wish to have golden crown fitted on tooth
2)Accounting services for People who are into e-Commerce services

A niche is the area of expertise in which you will specialize. Most online businesses choose a broad niche, then focus on something even more specialized within it. You will want to find one specific market that you can serve, repeatedly, rather than spreading yourself too thin by trying to operate in multiple niche markets. Not all the niches out there make for a profitable online business.
When you focus on a single niche, you can more easily identify your ideal customer and approach them with targeted marketing. That is essential to turning prospects into paying customers. It requires more complex advertising and SEO to put all those products in front of different customers, and more work to build relationships with those customers. Focusing on one niche does not stop your business from growing. Spreading yourself too thin is a mistake that causes many new businesses to fail, preventing you from connecting with customers and draining your budget before you can start making a process. Instead, if you focus on just one niche, you can keep your marketing as focused and simple as possible to reach a specific set of customers.
You can read more here: https://www.thebalancesmb.com/how-to-pick-a-profitable-niche-for-your-online-business-4000460
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath