There is search engine optimization and then there is search engine marketing which includes pay-per-click. If you don't have the time to keep up with the dynamics of seo you can elect to go to the pay per click business model to achieve results.
When done the correct way, pay-per-click (ppc) can be very profitable. It is suggested that you use a company that is experienced in this facet of search engine marketing for best results. Core Marketing is one such company.
