Both are effective methods of garnering visitors for a website, but one method can work very well for certain circumstances, while with the other, you may encounter difficulties generating traffic in the same situation.
Websites are virtual real estates. If you’re planning to sell your website for a premium price, you have to increase its value. There are many factors that can contribute to increasing its value. Among them are amount of traffic generated, consistency of traffic generated, page rank, search engine rankings over a period of time, link popularity, and the like. All of these fall in the realm of SEO.
Pay-per-click marketing is a method of advertising on search engine results pages. Basically, you bid to have your ads appear in the sponsored results when someone types in a query including your keywords.
PPC results are displayed above the organic search results. This prominent position means that in many cases, as much as 50% of the search traffic goes to the top 3 sponsored links. By being absent from PPC you're conceding loss of all those clicks to your competitors. If you're serious about maximizing your click-share of available searches for keywords relevant to your business, you absolutely must engage in PPC