While paid advertising can generate quick results, once you pull the plug on ad spend, the effects also stop.  So, you have to continuously spend on a paid ad campaign to keep getting desired results, which is not the case with SEO.  SEO is, to a great extent, a time-independent strategy; once your site takes top search engine spots, conversions start pouring in on autopilot.  Moreover, it has one of the best ROIs in the digital marketing space. And, done right, SEO can bring in high-quality leads to your business.