Though most of the proponents of SEO claim that SEO brings better and more effective result in the long run, yet it is quite common to see the business owners spend more on PPC than SEO with a common bias of getting faster and improved result with the former option. And quite obviously this results in a sharp decline with the business owners intention to pay any decent proportion for the SEO job to be done.
The fact is: SEO demands a specific technological skill set to get the website ranked in the search engine and to get targeted organic traffic to website. On the other hand, PPC needs a constant supply of money and mathematical calculation in order to achieve the goal. For PPC, the more you invest, the more you gain.
PPC is temporary solution and as long as you will supply the money, you will get the benefit. Once money is stopped, your benefits will be over. In fact, sometimes higher amount of payment even does not assure desired benefit.
On the other hand, when you employ SEO, you will get the return even when you are not actively working on it. Since with a properly executed SEO strategy brings organic customers to your site, the conversion rate would be much higher (as they are not just paid traffic). Therefore, if your conversion rate is 20% and you get 100 of organic traffic, you can make even more from your business than you actually spend on SEO.
In fact, this is not all. While you may easily get less conversion than 20%, you may make more as well. The fun part is you dont need to spend more to get more traffic, once your site is optimized. But for PPC, you need to spend continuously in order to stay alive. As you stop paying for advertisement, your traffic flow will be immediately stopped.
However, SEO takes time and also you cannot get instant result. Since there are too many self-proclaimed SEO gurus all around, it is hard to find the good ones. On the other hand, as the result is not immediate, you cannot actually judge anyone during initial days. So there is always a high risk of losing money and wasting time both are extremely valuable in business and life.
So, the better option, as most professionals find, is to employ both, without really overpowering one on another. Both are equally important and thus you need to invest your time and money on both in order to achieve good ROI for your business.