Any sites involved in marketing & online business needs SEO service to grow their business,sales & customers.If you've a site just for providing information to internet users on non-commercial basis then why you would spend some dollars on hiring SEO experts.
But every commercial sites will have to hire experts who can help them to bring their sites on top rankings on search engines,there by increasing the visitors & hence sales.Your competitors are ranking high on Google & doing nice sales by hiring SEO experts,so you would have to do the same thing to defeat your competitors.
