by third parties (e.g. if a commenter is trusted on your site), then there's no need to use nofollow on links; however, linking to sites that Google considers spammy can affect the reputation of your own site. No matter what niche your website is in, when you start writing an article, always provide helpful and actionable guidance. If you are giving the users the information they want, your content can be as long as you need. Producing content that ranks well is clearly an important part of writing for SEO. But it’s also about turning those visitors into paying customers.