SEO or search engine optimization is more effective compared to PPC. SEO helps to build your online identity and ranking in search engines. It helps to build your online reputation and generate more traffic and sales from good marketing techniques. PPC only helps to build your keyword popularity through successful campaigns.
When it comes to boosting traffic to your website, you have two basic options: pay-per-click (PPC) advertising or search engine optimization (SEO). You can pay for traffic using the PPC advertising programs provided by Google Adwords, Yahoo Search Marketing and others
PPC (pay per click) is you pay for google and your page will be top in the ad, but in return you will have fast customers and have a certain amount of traffic.
SEO is you have to spend time to put the site to the top by SEO technique ONPAGE and OFFPAGE. But if you already run PPC, it will be very good support for SEO.
If you have good capital then you should combine PPC and SEO for your website.