Here’s a high level way of thinking about marketing.
There is only one way to get your marketing noticed:

Deliver it where the people are.

Think about it, whether it is Google search, street signage, direct mail, or TV ads, the reason you market in certain ways is the same as Clyde Barrow’s answer as to why he robbed banks: Because that is where the money is.
Of course they need to be the kind of people you are looking for – the real prospects who need or want and can afford what you sell.
The more specifically your marketing is targeted to reach the EXACT right people, the more cost effective it is likely to be.
THAT is the core of what makes Google the huge success it is. Newspapers reach “everyone that reads newspapers in this town.” Think of all the wasted newsprint you are paying for! Same with just about any traditional advertising channel.
So there’s a second part of this, which is, if you can build something to attract your exact target market, you can get rich.
I know a company that made it big building an informative email newsletter for computer system administrators. They had 450,000 subscribers to whom they could sell things that sys admins would need and want.
It’s what makes Trade Shows work. Get people trying to sell and people looking to buy what they sell together, all in one place at one time. Make them BOTH pay for the privilege.
Think about how you can make this work for you.