On-Page SEO. On-Page SEO is important to ensure Search Engines can understand your content appropriately and help it rank for relevant keywords.
Site Usability. Site usability is important to maximize your available audience and minimize user bounce rates.
Site Performance. Site performance is important because you want to ensure your users have a great experience. Load speed can be a major issue too.
Social Media Activity. Social media activity is important for customer communication, and lack of a social media presence can also hurt your SEO ranking.