The main difference between search engine optimization (SEO) and pay-per-click (PPC) is that search engine optimization (SEO) can drive organic traffic which is free of charge while pay-per-click (PPC) gains paid traffic which you have to pay when users click on your advertisement. Besides, generating organic traffic reports for search engine optimization (SEO) is much more time-consuming than generating paid traffic reports from pay-per-click (PPC).