Yes, at least in the beginning. It takes a while for the SEO to kick in, and PPC helps seed the site with traffic, almost like priming a carburetor.
Our goal at Culture Cube is to develop your SEO to the point where PPC is optional. But even our most successful clients choose to continue PPC campaigns if the ROI is good.
Search-optimized pages are better destinations for PPC because they convert at a higher rate, and their relevance reduces the cost of a bid. We sometimes create search engine-friendly pages primarily for PPC. When they also drive organic traffic, that’s a bonus.