Stats: show subscriber acquisition source

[simison]

To show value as a platform and help publishers optimize their site for getting more subscribers, we should better communicate customer how they gained the subscriber. Was it subscribe modal, welcome overlay, blogroll, recommendation by other publisher, Reader, etc?

Especially when we have "network effect" type features, these stats will be important for showing the network effect's impact.

Context, internal references:

• p58i-exh-p2
• p58i-eHZ-p2
• pedxs5-9u-p2
• peKye1-CC-p2

Designs

Figma: S4xGQTEkLhYdUvcIdn2Cfr-fi-1_32846

i1: p1HpG7-v7v-p2
i2: p1HpG7-vch-p2

[github-actions]

OpenAI suggested the following labels for this issue:

• [Feature Group] User Interaction & Engagement: The issue discusses how to communicate subscriber acquisition sources, which directly relates to user engagement on the platform.
• [Feature] Stats Data: The request is to show detailed statistics about how subscribers were acquired, which relates directly to tracking traffic and insights.
• [Feature] Subscriptions: This is relevant because the focus is on understanding subscriber acquisition, which is a core aspect of subscription-based services.

[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?