Yes, you can invest in SEO for your business. Search engine optimization allows you to increase traffic without having to pay for each individual click.
When you run PPC ads, you'll be paid for each and every click that comes through that channel to your website. This traffic, on the other hand, is effectively free if the website ranks organically in the search engines (at least in terms of a cost-per-click). Of course, ranking a website on the SERPs necessitates an investment in skills and resources.
If you can get your website to the top of the search engines, you'll get a steady stream of traffic that won't cost you anything to click on and won't stop even if the advertisements are switched off. If you rank organically, you'll have visibility 24 hours a day, seven days a week.