There are three main ways for clients to find a website: direct navigation, referrals from other sites, and search engines. Measuring traffic sources using analytics helps optimize marketing. Search engine optimization (SEO) involves modifying web pages to rank higher organically in search results. SEO is important for increased visibility, more visitors, and greater brand exposure leading to more sales. Key SEO components include on-page elements, off-page links, and paid search ads. Prioritizing traffic sources like SEO, referrals, and paid search helps grow a business.