Recently, we looked at a debate over what is better between search engine optimization and pay-per-click. Of course both should be used typically. The general consensus seems to be that you should use both when possible, but that SEO is better for the long term, and PPC is better for quick results.
On the SEO front Google is making changes that could have some effect on the success of organic rankings. One of these changes is the introduction of personalized search to all Gooogle users. You no longer have to be signed in for Google to personalize your results, and that means it is much more important to get that first click from a user.
On the other hand, the usefulness of PPC to people who are just establishing themselves on the web. The reality is that SEO takes time, and while it is of great importance and provides long-term benefits, it is very hard to be competitive right out of the box.
When you have a brand new domain name, a new site, and no links, you're probably going to have a hard time jumping up in the rankings for any competitive keywords. PPC lets you do it and start getting your ROI quickly.
SEO is an absolute must when dealing with new web sites. None of the search engines are going to rank you very high in the organic searches if you are not meeting their criteria. And...the Organic search results are 24 hours per day ads. Not so with PPC, unless you are dealing with an unlimited budget.
PPC should be used after SEO to target special sales, or services. It is a great way to help searchers locate your products when they are on sale, or your services when a special price can be obtained.