Last week we measured how fast your ecosystem gets a customer from need to signed deal. This week: what happens after the signature, which is where most partnership measurement quietly gives up.

The claim under test this time is bigger than speed. It is the claim that partners make customers more successful, not just easier to acquire. The Customer Success Index, CSI, is our attempt to make that claim falsifiable.

What CSI actually measures

CSI is a weighted average over five components of a customer’s health, scored 0 to 10:

1. Product adoption. Is the customer actually using what they bought?

2. Engagement quality. Are the delivery engagements around this customer healthy, moving, and completing?

3. Advocacy. Has the customer become a reference, a case study, a referrer? Advocacy is the strongest lagging indicator of success there is, because nobody advocates for a product that is failing them.

4. Business outcomes. The commercial trail: renewals, expansion, realized value.

5. Customer sentiment. What the customer says when you ask, folded in from survey responses and support experience.

Each component gets a weight, and the weights are yours to set. A product-led company might load adoption; a services-heavy one might load engagement quality. The defaults are sensible, but the point is that “success” is defined by you, in configuration, not hardcoded by us. That will be a recurring theme in this series: the platform computes, the client defines.

The honesty rule: missing data is missing

Here is the design decision we sweated most, and the one I would push any vendor on if I were evaluating tools in this category.

What should a success score do when a component has no data? Say you run no surveys, so there is no sentiment signal at all. Most scoring systems quietly substitute a neutral value, a 5 out of 10, and roll it in. The result looks complete and is subtly fabricated: your score now contains a number nobody measured.

CSI refuses to do that. A component with no data is excluded, and the weights renormalize over what is actually present. Run no surveys and your CSI is a real average of the four components you do measure, not four real numbers plus one invented one.

And there is a floor. If too little of the weighted picture is present, the score is withheld entirely. Not zeroed, not defaulted: withheld, with a list of exactly which inputs are missing. An empty score that tells you why it is empty is more useful than a fabricated one that tells you nothing.

We removed every trace of neutral filling from the calculators some releases ago and never looked back. If a metric is going to sit in a quarterly review and drive decisions about partners and customers, every digit in it has to trace to something that happened.

Where partners come into it

CSI is a customer score, but its purpose is a partner question: which partners are attached to customers that succeed?

Line up your partners against the CSI of the customers they touch and the four depths of partnership become visible in your own data. A transactional partner (depth one) shows up at acquisition and vanishes; the CSI of their customers is whatever your own team makes of it. An implementation partner (depth two) lifts early adoption. A success-level partner (depth three) leaves fingerprints across adoption, engagements, outcomes, and eventually advocacy. That difference, visible per partner on a dashboard rather than asserted on a slide, is what lets you invest in depth instead of just counting logos.

This is also the pairing that makes last week’s metric honest. A high CDE with a low CSI means your ecosystem finds deals quickly but hands over customers who then struggle. Speed of discovery is the door; lifecycle contribution is the house. You want both numbers, side by side, before you call a partnership strategic.

What to do with your number

• Score withheld? Read the list of missing inputs as a to-do list. Usually the first gap is sentiment: a simple recurring survey fixes it in a quarter.

• High CDE, flat CSI: stop widening the funnel and start asking what happens in onboarding. The partners you need next are implementation and success partners, not more referrers.

• CSI rising where a specific partner is involved: that partner is quietly doing lifecycle work. Name it, measure it, and build the relationship deeper. This is the L3 conversation, and most ecosystems never have it because nobody had the number.

As with CDE, you can approximate this in a spreadsheet: five columns, your own weights, and the discipline to leave cells blank instead of guessing. If you would rather have it computed continuously per customer and per partner, with the missing-input list telling you what to instrument next, that is what Entwine does. The free workspace monitors five relationships, no credit card: entwineapp.io.

This is part 2 of a series on the three ecosystem metrics. Part 1 covered CDE, Customer Discovery Efficiency. Next: ECS, the Ecosystem Completeness Score, and the uncomfortable question of how much of your customers’ needs your ecosystem cannot yet meet.

Every partnership leader says some version of the same sentence in the quarterly review: “partner-sourced deals close faster.” Heads nod. Nobody asks the follow-up, because nobody can answer it: how much faster, measured how, compared to what?

That gap has a name in our world: Customer Discovery Efficiency, or CDE. It’s the first of three ecosystem metrics we build Entwine around, and it’s the simplest to explain, which is exactly why it’s the right place to start this series.

The question CDE answers

A customer with a problem takes one of two roads to your solution. The direct road: they find you, you qualify them, you run your process. The ecosystem road: a partner who already has their trust says “talk to these people, this is your problem’s shape.”

CDE measures the difference between those roads. Not anecdotally — arithmetically:

CDE = average days-to-close for direct deals ÷ average days-to-close for ecosystem-sourced deals

Closed-won deals only, on both sides. A CDE of 1.0 means your ecosystem road is no faster than the direct one. A CDE of 2.0 means a customer who arrives through your ecosystem gets from need to signed solution in half the time.

Three things about that formula matter more than the formula itself:

1. It only counts what happened. CDE is computed from your actual opportunity records, including created dates, close dates, and who referred whom. No sentiment weighting, no “estimated influence,” no model deciding a partner probably helped. If the score is empty, it’s because the data is, and that emptiness is information too.

2. “Ecosystem” is wider than “partner.” The deals on the ecosystem side of the ratio are segmented by referrer type - partner-referred, customer-referred, and other-referred - against purely direct deals. Your happiest customer is part of your ecosystem’s discovery engine whether or not anyone gave them a partner tier. Most measurement frameworks miss this entirely; the referral your customer made last quarter is doing the same work your partners do.

3. Averages lie, so keep the median in view. One whale deal that closed in a week can flatter an average. We compute the median days-to-close alongside the average for both roads, so a single outlier can’t manufacture an efficiency story. If your average says 2.1× and your median says 1.2×, you don’t have an efficient ecosystem, you have one great story and a measurement habit to fix.

Why speed, of all things?

Because discovery speed is the one benefit of an ecosystem that shows up before revenue attribution fights start. Sourced-revenue percentages descend into arguments about who touched what. Days-to-close is harder to argue with: the deal either spent 90 days in your pipeline or it didn’t.

And it compounds quietly. If ecosystem-sourced deals close in 60 days against 100 direct, that’s not just 40 days of sales cost saved, it’s a customer who spent 40 fewer days with an unsolved problem. That’s where partnership measurement usually stops and customer-success measurement should begin, the “partnership paradox” we’ll take apart properly in the next piece.

What to do with your number

• No number at all? Your opportunities aren’t recording a referral source. Fix the habit before the metric; a quarter of honest data beats a year of backfilled guesses.

• CDE ≈ 1.0 means your ecosystem isn’t accelerating discovery-to-close. That’s not a verdict on whether partners create net-new demand, only a second lens (volume, win rate, source uniqueness) can tell you that. It’s a signal to look closer, not a conclusion.

• CDE comfortably above 1: you’ve earned the next question, which is whether those faster-won customers also succeed faster and stay longer. Speed of discovery is the door; lifecycle contribution is the house. That’s the second metric - the Customer Success Index - and it’s next week’s letter.

You can compute CDE for your own book with a spreadsheet, two columns of dates and a referrer tag, and honestly, you should, this week. If you’d rather have it computed continuously - per partner, medians and all, on a live dashboard - that’s what we built Entwine for. The free workspace monitors five relationships, no credit card: entwineapp.io.

This is part 1 of a series on the three ecosystem metrics — CDE, CSI (Customer Success Index) and ECS (Ecosystem Completeness Score) — and the four depths of partnership they measure.