First starting out, I relied solely on cl ads as I wasn't about to lay money out for advertising.
Once I got word of mouth and repeats I slowed it down. It worked. You will get 'cheaps' but know that going in. You're always going to have the hacks to compete with. I raised my prices. Smart folks understand you get what you pay for.
I had a really good client review me on yelp, at the time I had no idea what that was, and it increased business. Now, if yelp would unfilter my ads I may consider advertising with them.
You should be aware of your competition, but don't be so quick to match prices.
Folks who are only interested in price are usually the most difficult to please. I usually refer them to the neighborhood tunnel wash. And yes I've been blunt and explained to them that they sound like price is their sole motivating factor in deciding on a detailer. Educate your clients. Washing cars isn't detailing. When we have that conversation, some see the light, others go cheap. Sometimes, not all the time, I hear back from them. ; )
