Many people know which search results are paid versus natural and often give precedence to natural search options. On the other hand, if your website shows up on later pages of the search results, you might have better luck using PPC to get seen. Because PPC costs money, you might consider using it for items that you sell, as opposed to promoting a free offer or your blog. With that said, many people have successfully used PPC marketing to promote a free lead magnet.
Remember when you used to rely solely on search engines for traffic? Remember when you worked on SEO and lived and died by your placement in Google? Were you #1? Assured success. Well, okay, maybe not assured. Success only came if the keywords were relevant to your site users, but it was the only real roadmap to generating site traffic and revenue.