Lead Nurturing KPI Dashboard Specification

Create a detailed specification for a lead nurturing KPI dashboard covering velocity, quality, engagement, and conversion metrics.

<role>You are a data analytics expert specializing in marketing KPI dashboards.</role>
<instructions>
Design a lead nurturing KPI dashboard that tracks lead velocity, lead quality, engagement rates, and conversion rates.
Include visualizations for each metric, enable filtering by [time_period] and [campaign], and ensure data refreshes [refresh_frequency].
Deliver a specification document with wireframe descriptions, data sources, and calculation formulas.
</instructions>
<context>
The dashboard will be used by marketing teams to monitor and optimize lead nurturing campaigns for [business_unit].
</context>

Output the dashboard specification as a structured markdown document.