You can advertise on the internet. You don't have to pay anything for this except for setup costs. This at minimum is to get your business known on Google, Yahoo, Bing. For a small fee of $25, I will set you up. You don't need to have a website to be able to take advantage of the internet.
Once this information is added to the search engines, they in turn will sell this information to other companys. Within months of this, your business will be added to the data which is available on your GPS units. So for example, if you business is tire repair. Currently the only people who will know that your business exists are the people who drive past your business. but if you take advantage of adding your business to the internet. In short time, your information will be available to anyone using a smart phone, GPS unit and if they are looking for a tire repair, your business will then appear. This will improve your chances of increasing your income while not draining your pocket of advertising money.
But if you do have some money to spend on advertising, then you would want to look into Google Adwords. This cost money, the money charged is dictated by the amount of money which you setup within your profile.
For example, if we continue with the tire repair business. Say you can handle multiple kinds of tire repair, like say car tires, truck tire, run-flat tires...etc. Within the profile we would be more specific of what the business does. Google makes money by the click of an ad. If the ad is not clicked, then this will not cost you anything.
How does this cost influence the query results within Google? If we typed "tire repair" in the google search box and hit enter. A result will come back showing all kinds of information about tire repair. What you need to know is, the results are broken down into 3 segments. The very top rows are businesses which are paying for adwords. next will be the businesses know within the search engine as mentioned in the top paragraph, then we will see all other results. Then the information presented on the right hand side are also adword customers.
The more money you are willing to spend for a single click, the closer to the top of the first page you will get. Google has an estimated cost for a search word. So they may say that "Tire Repair" will cost 50 cents per click for example. You would then say you are willing pay 15 cents. So the results will then show the business which are willing to pay the most to the least amount. So this takes time to fine tune the cost per click to see what it gets you within a search result. But remember you don't have to pay 50 cents.
Your competion will be other businesses within 25 miles of you, then the search then goes further away. So if you don't have any competion within 25 miles, then you could then be paying 5 cents per click and end up being the first business shown on page 1 for example. For this I would charge $25 dollars an hour which I work on finetuning and setup of your account. Once setup, you might not have to do anything for years, so there would not be any more expense by me. But your Adword cost would continue whenever someone click on your ad.