Pay-Per-Click vs. Organic SEO - What is the difference

Many times I am asked about the difference between PPC (Pay-per-click) and Organic SEO, (sometimes referred to as natural SEO). Actually, many times the individual asking the question doesn't really know what they are asking. We discover that they are interested in ranking for keywords on search so it comes to natural SEO and Paid Placements.
Now in 2010 the search landscape has become more complicated, with Universal search results and local listings taking such an active role in our Google search results. However, to keep things simple to understand for the layman, we will just concentrate on PPC vs. Organic SEO.

What is Organic SEO?
Wikipedia defines Organic, or Natural SEO as the process of improving the visibility of a web site or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. Other forms of search engine marketing  (SEM) target paid listings. In general, the earlier (or higher on the page), and more frequently a site appears in the search results list, the more visitors it will receive from the search engine.

What is Pay-Per-Click Marketing?
PPC advertising, as it is commonly referred to, is an advertising  model, in which the advertisers place their ads on affiliate or host websites and only pay when their ad is actually clicked by a user. With search engines (IE. Google), advertisers typically place bids on keywords and/or phrases which are relevant to their products, services or target market.
 

The Screen shot below is probably the easiest way to illustrate the results:



One of the biggest differences is that the PPC allows any website (that is still relevant) to show up near the top in the search results as long as they have followed Google's guidelines relatively quickly (within minutes or hours of launching a campaign). Whereas, natural SEO may take very long, depending on the competitiveness of your industry, to begin showing results. The benefit with organic is that you do not have to pay for the actual clicks once you have made it to the top.

The best approach will incorporate both an organic seo strategy and a PPC marketing campaign. This will allow you to garner immediate results and a long-term strategy.