It depends very much on the type of business, for web design I would look into other forms of advertising than PPC. Regardless, SEO is important. PPC can seem cheap at first but can actually end up being very expensive when you consider how many clicks you're going to pay for before you convert one of them to a web design client. I've been able to get much more targeted on social media platforms resulting in more relevant visitors who end up being cheaper to convert to business.