Sankey diagrams give you x-ray vision for your customer journey
"Everything Starts Out Looking Like a Toy" #109
Hi, I’m Greg 👋! I’ve written 100+ essays on product, data, and process for an idea or future product direction, often data between systems. System “handshakes”, the expectations for workflow, and data tasks are some of the things I write about frequently.
Read more: What is Data Operations?
This week’s toy: JSON Crack might have a slightly odd name, but is a really interesting utility to visualize the contents of a JSON blob as a series of nodes in a graph. With this utility, it’s a lot easier to see (and traverse) a very large JSON structure. Add some indexing and searching and this utility might start acting like a stand-alone JSON viewer. The one-day-delayed Labor Day Edition 109 of this newsletter is here - it’s September 6, 2022.
The Big Idea
A short long-form essay about data things
⚙️ Sankey diagrams give you x-ray vision for your customer journey
Attribution – the process to understand the source of a conversion – is complicated. In a lead process (or any other process), everyone wants to know what contributed most to a successful conversion. The problem is that there are often many different factors that result in conversion. This analysis is multivariate. There appears to be one thing that caused the conversion (maybe the last thing before it happens). But there might be additional unseen reasons that a conversion occurred.
To handle this multi-stage process, many organizations default in the prospect process to simplifying the customer journey. They track the first seen source for a lead or the last item directly before a conversion action occurs. When you track first seen or most recently only, it’s easier. In a customer journey you either constantly write a source only once (first seen) or you overwriting the value whenever you see something new. In the latter process, you stop rewriting the value when the process ends through conversion or abandonment.
Simplifying attribution improves the ability to see where a lead came from most recently. You always know where the conversion originated because you have the definitive value. Depending upon your tactic, you will have either the most recent time you saw a source or the first time you saw a source.
The problem with storing a single attribution value
Here’s a small wrench in that argument. When you track attribution, you don’t know where the important thing happened on the multi-step prospect path your prospect took. The thing you want to find is the most meaningful part of that journey, whether it resulted in conversion or not.
The customer journey is a winding road, or a straight one, and it’s difficult to predict in advance. One way to track multiple customer events is to count all of them. You end up creating a table counting the number of times a prospect passes through a particular event and focus on the segment of prospects that convert. (For those who use Salesforce, this is akin to using a change history table to track changes in a particular field and generating a list of possible paths to goal.)
Another way to do this analysis is to use a Sankey diagram. Named for a ship captain who created a diagram of steam engine efficiency, a Sankey diagram is a visualization that shows the flow of information between nodes in a graph while also displaying the volume of that information. Sankey diagrams follow the river of information for the customer journey as it happens and demonstrate signposts along the way.
One famous example of a flow graph that resembles a Sankey diagram is this illustration of Napoleon’s invasion of Russia.
The visual demonstrates the track of the army through Russia and the number of soldiers who remained on the retreat. By showing the flow and change of the information as a time series, you get a real sense of the situation that a static table of changing information at different time intervals cannot provide.
Why use a Sankey Diagram?
Sankey diagrams help you tell the story of your data. If you’re attempting to model a customer journey, seeing a visual flow of the information may highlight important edge cases and also give you a sense of the most likely outcomes at a glance. Adding a filter for user attributes to your data visualization will let you look at a lead segment at any point in the customer journey and compare the from node, the to node, and the weight.
So what? A downward change in the weight of a node as you move from stage to stage suggests either a dropoff by abandonment or a new path in your customer journey that you have not yet considered. In contrast, a stage that gains weight from multiple sources could be a popular destination in the customer journey or perhaps simply a red herring (lots of people end up on a pricing page). It’s the next stage beyond that one that is interesting, as you can see if there is a subsequent dropoff in the funnel.
Combining filters with the visual explanation you get from a Sankey diagram lets you see in more detail when there are different kinds of journeys happening and overlapping in your overall customer journey. Seeing paths by persona or paths by initial entry point will help you to find leaks in the funnel or areas where you want to increase your investment.
Finally, Sankey diagrams let you avoid the false positives happening today in your data when you get a lot of traffic from a single source – an ad campaign or a content item or an event – and you don’t know exactly where that traffic goes. By overlaying the events and paths you do know about with the hidden events and paths emerging in your systems, Sankey diagrams give you a kind of x-ray vision into the customer journey.
What’s the takeaway? Sankey diagrams are an effective way to show information where the paths are varied and the team would like to analyze the best path to a goal. Because this visualization shows all the paths at once, filtering the the underlying information is an effective way to uncover what’s going on.
Links for Reading and Sharing
These are links that caught my 👀
1/ Writing to think - Herbert Lui’s essay on writing really resonated with me. Writing, Lui argues, is the cause of better thinking and not the other way around. This sounds pretty odd to some people because they believe the thought process happens first. I’m here to tell you that often my best thinking comes from the process of writing things down. (It’s why I started this Substack). Read the essay and let me know what you think. Or even better, read the essay, write some thoughts down, and then tell me what you think about it.
2/ First principles for spreadsheets - Jeffrey Perkel has suggestions to make your spreadsheets better. Separate your data from your transformations, Perkel argues. This one is key because it always allows you to go back to where you started without losing the original source. Perkel also reminds you to document, well, everything. When you have a complicated formula or a bit of logic, future you will thank you when you insert a note to remind yourself how to do this magic again.
3/ Calculating Cohorts: a Primer - I really appreciate it when data wizards write out a cookbook on how to do useful things. One great example is Olga Berezovsky’s “How to Measure Cohort Retention”, where you learn how to track the progress of users from initial discovery through to abandonment. This article is fantastic in enumerating the terms and definitions of cohorts and also in discussing how to use this information in the real world when it arrives from disparate systems.
What to do next
Hit reply if you’ve got links to share, data stories, or want to say hello.
Want more essays? Read on Data Operations or other writings at gregmeyer.com.
The next big thing always starts out being dismissed as a “toy.” - Chris Dixon
Amazing article. thanks a lot for writing it.
As a data analyst, I definitely agree with the lack of information a single attribute value provides.
I've been using Sankey diagrams for behavioral analysis for various app companies I've worked with, and I can say the findings are often very insightful (and completely unexpected!). For instance, I once found that new users where getting stuck into a loop during the onboarding process. This would have been close to impossible to find without flow charts.
By the way, SankeyJourney is a great tool to generate Sankey diagram to visualize customer journeys in seconds (sankeyjourney.com)