PAGE VIEWS - Page views tell you how many and which of your content pages your visitors are consuming, which can help you identify the content that's performing well.
UNIQUE VISITORS - Page views can be skewed by visitors who click through several pages or repeat visitors. So Unique visitors stats tell you the overall size of your audience and how much of your traffic is repeat visitors.
AVERAGE TIME ON PAGE - Average time on a page gives you insight into whether people are quickly skimming your content or sticking around to consume it more slowly.
EMAIL OPENS - Email tools like MailChimp, Marketo, Eloqua, Pardot or Act-On can tell you how many people opened your email and at what time. This offers insight into the best time of the day to send emails and effective subject lines.
EMAIL CLICKS - Those same email tools can tell you which links within your email were most popular, which could help you choose more clickable links and anchor text for the future.
ASSET DOWNLOADS / FORM COMPLETIONS - For gated content, you can use your marketing automation tools to measure form completions; In other words, how many times someone fills out the form preceding the content completely and with valid information.