Advertising is not an efficient way to find customers. When businesses like Apple and Verizon are throwing off a ton of cash, it makes sense to use that cash to cement awareness of their products and services.
For the rest of the world, acquiring customers is a dialogue. You need just enough attention to get a conversation going. And you can't converse with 100 people, so why spray thousands of messages out there? Yes, we need to promote our businesses, but start where you live, and make sure your friends and family understand your business. Once they can explain it to others, then you've begun advertising.
This article from Kontny offers sound advice on many issues confronting an entrepreneur.
Signal v. Noise: Tips for getting clients? Sell cake. 2015-Dec-15 by Nathan Kontny
I remember sitting across from the owner of a bar in my neighborhood. He didn’t have a need for the product I was selling, but in that conversation he outlined exactly what he had a need for that he would buy from me. That conversation was great feedback to help me mold who I was trying to help, and if I had given up on that idea, this guy had just given me the next thing to work on and he would have been my first customer.