Path Design maps out the different stages that compose the user's timeline from starting point to Beneficial Outcome. A key measurement in Performance Valuation, therefore, is step drop-off — "how many people are making it from step to step over time?"
If you're tracking the drop-off rate from one step to the next, it's easy to pinpoint the parts of the path that most need improvement. Especially because the drop-off rate tends to follow a consistent pattern from cohort to cohort.
Step drop-off is counterintuitive to the idea of picking a "milestone event" along the user timeline and optimizing it in isolation. You can't just say, for example, "Well, we looked into it and if you send five emails within six days after signing up, then you're more likely to convert. So let's just try to mash everybody through that process." That doesn't tell you why somebody is doing what they're doing.
Even a business-driven milestone event, like signup-to-paid conversion, cannot be meaningfully impacted in isolation. Signup-to-paid conversion is just another sub-outcome which can be improved only with an understanding of the steps that precede and follow it.
We recommend seeing each step in the user's timeline as a conversion event — users are converting to the current step from the previous one. Getting an understanding of the drop-off from one step to another gives you a handle on process questions, and process improvements are by far the most effective way to expose more users to more steps in the value path.
From: VPP Episode 04 (24.35)