If your website focuses on content for readers or viewers, change this back-end setting in Google Analytics 4 to better understand your most valuable audience.
ConvertKit is an excellent ESP for subscription-focused businesses growing a product offering alongside their mailing list.
KPIs are also fantastic when programming a computer or optimizing an advertising algorithm. For content analytics, however, single KPIs are a bad choice.
VWO makes the process of A/B testing website and app content fairly simple, providing easy WYSIWYG solutions for many visual website changes. Read The Content Technologist review.
RankScience is an A/B testing tool for SEO snippets and structure. Read The Content Technologist review.