With the right targeting, you can run a Facebook at 2 people.
You can get out a pen and paper and write down 10 emails, then upload them to Facebook, then run ads right at those people (or at least a quarter of them). Now try it with 10,000.
You can run a video on Facebook, boost it, then run ads just at those people who watched at least 50% of the video. If the call-to-action is an invitation to watch another video, your odds are good.
That's not to say you should go out and run Facebook ads; that's a marketing tactic and I don't know what your marketing strategy is.
In MeatBall Sunday, Josiah Wedgwood is cast as the first marketer. But it wasn't until the early-middle of the 20th century that people began to think of themselves as "marketers". They were employees of major US consumer goods manufacturers, conducting large-scale market research in order to improve products. Better tasting toothpaste. Soda cans with a more satisfying "ker-chuck" when you crack them open.
These early marketers improved "Four P's of Marketing". In order of importance: Product, Price, Promotion, Place. Nothing has changed since those 4 P's were codified in 1961.
Facebook advertising can teach you about a form of promotion that is usually called retargeting or remarketing, though I like "warm advertising". It's for people who already know your name, as in the Facebook-boosted video scenario above. This is as opposed to "cold advertising".
It's obvious why Big Tech has made retargeting available on their platforms: it's the way to monetize unrealized, unconsummated, partial interest in what you sell. So you can buy it on Facebook, Instagram, Amazon.com, Google properties, the App Store, Bing properties, and LinkedIn.
Whatever your marketing strategy, warm advertising is likely a desirable tactic - if you have done the work of building a long-term marketing program. It's value-added on the core marketing functions: improving your product, cultivating your expertise, honing your pricing, crafting your messaging and brand identity, and creating a content marketing strategy that inspires.
If all that stuff is the cake, warm advertising is the icing (just like SEO).
What's your path to a place where warm advertising makes sense, adds value, and lets you tap all that unmonetized interest in what you do?