Stats: subscription stats UX issues

[simison]

See design P2, internal reference: p1HpG7-v7v-p2

List of small issues around subscriptions:

• Stats: Rename "Subscribers" → "Newsletters" #40537
  
• Emails/Subscribers tab consolidation (possibly done already -> review placements and copy)
  
• Stats: Show % instead of just absolute numbers of for open/click rates. Show absolute numbers on hover. #40538
  
• Link to posts from Emails list -> exists arleady, but review UX #40608
• Remove redundant data (Today, 30 days ago, 60 days ago and 90 days ago)
• Introduce Key Metrics at the top to give a quick overview of newsletter performance.
  
• Link Subscriber to individual subscriber stats page. Jetpack Cloud for Jetpack, Calypso for WP.com.
• Show subscriber name > email instead of username, which is often randomly generated
• Show “Sending” for a few minutes (5?) after posting before showing “sent” stats to avoid showing in-progress numbers
• Paid subs+free subs graph; free subs looks flat when I have paid subs and enabling/disabling stats is clunky. Upgrade stat graph; work with Red to land on something that's reasonable technically and aligns with future for other graphs in the shared graph library.
  
• Explore showing "subscribed via" -source; we track this already for ourselves but might require adding a database for customers.
  

Single email issue view

• Consolidate Clicks & Open stats for a single email stats view; currently they're split between two tabs
  

• Explore showing 24-hour chart!
  

[github-actions]

OpenAI suggested the following labels for this issue:

• [Feature Group] User Interaction & Engagement: The issue discusses various user experience concerns related to subscription stats and how users engage with the subscription features.
• [Feature] Subscriptions: The content focuses on issues related to subscription management and user experiences with email and subscriber stats.
• [Feature] Stats Data: The mention of subscriber statistics and tracking in the issue directly relates to the Stats Data feature.

[github-actions]

This issue could use some more labels, to help prioritize and categorize our work. Could you please add at least a [Type], a [Feature], and a [Pri] label?