EDA in Public (Half 3): RFM Evaluation for Buyer Segmentation in Pandas

January 1, 2026

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! For those who’ve been following alongside, we’ve come a great distance. In Half 1, we did the “soiled work” of cleansing and prepping.

In Half 2, we zoomed out to a high-altitude view of NovaShop’s world — recognizing the large storms (high-revenue nations) and the seasonal patterns (the large This fall rush).

However right here’s the factor: a enterprise doesn’t truly promote to “months” or “nations.” It sells to human beings.

For those who deal with each buyer precisely the identical, you’re making two very costly errors:

Over-discounting: Giving a “20% off” coupon to somebody who was already reaching for his or her pockets.
Ignoring the “Quiet” Ones: Failing to note when a previously loyal buyer stops visiting, till they’ve been gone for six months and it’s too late to win them again.

The Resolution? Behavioural Segmentation.

As a substitute of guessing, we’re going to make use of the information to let the purchasers inform us who they’re. We do that utilizing the gold commonplace of retail analytics: RFM Evaluation.

Recency (R): How just lately did they purchase? (Are they nonetheless engaged with us?)
Frequency (F): How usually do they purchase? (Are they loyal, or was it a one-off?)
Financial (M): How a lot do they spend? (What’s their complete enterprise impression?)

By the top of this half, we’ll transfer past “High 10 Merchandise” and really assign a selected, actionable Label to each single buyer in NovaShop’s database.

Knowledge Preparation: The “Lacking ID” Pivot

Earlier than we are able to begin scoring, we now have to handle a choice we made again in Half 1.

For those who bear in mind our Preliminary Inspection, we seen that about 25% of our rows had been lacking a CustomerID. On the time, we made a strategic enterprise determination to hold these rows. We would have liked them to calculate the correct complete income and see which merchandise had been fashionable total.

For RFM evaluation, the foundations change. You can’t monitor conduct with no constant id. We are able to’t understand how “frequent” a buyer is that if we don’t know who they’re!

So, our first step in Half 3 is to isolate our “Trackable Universe” by filtering for rows the place a CustomerID exists.

Engineering the RFM Metrics

Now that we now have a dataset the place each row is linked to a selected particular person, we have to mixture all their particular person transactions into three abstract numbers: Recency, Frequency, and Financial.

Defining the Snapshot Date

Earlier than calculating RFM, we’d like a reference cut-off date, generally referred to as the snapshot date.

Right here, we take the newest transaction date within the dataset and add in the future. This snapshot date represents the second at which we’re evaluating buyer behaviour.

snapshot_date = df['InvoiceDate'].max() + dt.timedelta(days=1)

We added in the future, so prospects who purchased on the newest date nonetheless have a Recency worth of 1 day, not 0. This retains the metric intuitive and avoids edge-case issues.

Aggregating Transactions on the Buyer Stage

rfm = df.groupby(‘CustomerID’).agg({
‘InvoiceDate’: lambda x: (snapshot_date — x.max()).days,
‘InvoiceNo’: ‘nunique’,
‘Income’: ‘sum’
})

Every row in our dataset represents a single transaction. To calculate RFM, we have to collapse these transactions into one row per buyer.

We do that by grouping the information by CustomerID and making use of completely different aggregation capabilities:

Recency: For every buyer, we discover their most up-to-date buy date and calculate what number of days have handed since then.
Frequency: We depend the variety of distinctive invoices related to every buyer. This tells us how usually they’ve made purchases.
Financial: We sum the whole income generated by every buyer throughout all transactions.

Renaming Columns for Readability

rfm.rename(columns={
'InvoiceDate': 'Recency',
'InvoiceNo': 'Frequency',
'Income': 'Financial'
}, inplace=True)py

The aggregation step retains the unique column names, which could be complicated. Renaming them makes the dataframe instantly readable and aligns it with commonplace RFM terminology.

Now every column clearly solutions a enterprise query:

Recency → How just lately did the client buy?
Frequency → How usually do they buy?
Financial → How a lot income do they generate?

Inspecting the Outcome

print(rfm.head())

The ultimate rfm dataframe accommodates one row per buyer, with three intuitive metrics summarizing their conduct.

Output:

Let’s stroll by means of this the way in which we’d with NovaShop in an actual dialog.

“When was the final time this buyer purchased from us?”

That’s precisely what Recency solutions.

Take Buyer 12347:

Recency = 2
Translation: “This buyer purchased one thing simply two days in the past.”

They’re contemporary. They bear in mind the model. They’re nonetheless engaged.

Now examine that to Buyer 12346:

Recency = 326
Translation: “They haven’t purchased something in nearly a yr.”

Though this buyer spent lots prior to now, they’re at the moment silent.

From NovaShop’s perspective: Recency tells us who’s nonetheless listening and who would possibly want a nudge (or a wake-up name).

“Is that this a one-time purchaser or somebody who retains coming again?”

That’s the place Frequency is available in.

Look once more at Buyer 12347:

Frequency = 7
They didn’t simply purchase as soon as — they got here again repeatedly.

Now have a look at a number of others:

Frequency = 1
One buy, then gone.

From a enterprise perspective, frequency separates informal buyers from loyal prospects.

“Who truly brings within the cash?”

That’s the Financial column.
And that is the place issues get attention-grabbing.

Buyer 12346:

Financial = £77,183.60
Frequency = 1
Recency = 326

This tells a really particular story:

A single, very massive order… a very long time in the past… and nothing since.

Now examine that to Buyer 12347:

Decrease complete spend
A number of purchases
Very latest exercise

Necessary perception for NovaShop: A “high-value” buyer prior to now isn’t essentially a beneficial buyer at this time.

Why This View Modifications the Dialog

If NovaShop solely checked out complete income, they may focus all their consideration on prospects like 12346.

However RFM exhibits us that:

Some prospects spent lots as soon as and disappeared
Some spend much less however keep loyal
Some are energetic proper now and able to be engaged

This output helps NovaShop cease guessing and begin prioritizing:

Who ought to get retention emails?
Who wants reactivation campaigns?
Who’s already loyal and needs to be rewarded?

Proper now, these are nonetheless uncooked numbers.

Within the subsequent step, we’ll rank and rating these prospects, so NovaShop doesn’t must interpret rows manually. As a substitute, they’ll see clear segments like:

Champions
Loyal Clients
At-Threat
Misplaced

That’s the place this turns into an actual decision-making instrument — not only a dataframe.

Turning RFM Numbers Into Significant Buyer Segments

At this stage, NovaShop has a desk stuffed with numbers. Helpful — however not precisely decision-friendly.

A advertising and marketing crew can’t realistically scan a whole bunch or 1000’s of rows asking:

Is a Recency of 19 good or unhealthy?
Is Frequency = 2 spectacular?
How a lot Financial worth is “excessive”?

Our aim is to rank prospects relative to at least one one other and switch uncooked values into scores.

Step 1: Rating Clients by Every RFM Metric

As a substitute of treating Recency, Frequency, and Financial as absolute values, we have a look at the place every buyer stands in comparison with everybody else.

Clients with more moderen purchases ought to rating increased
Clients who purchase extra usually ought to rating increased
Clients who spend extra ought to rating increased

In follow, we do that by splitting every metric into quantiles (often 4 or 5 buckets).

Nonetheless, there’s a small real-world wrinkle. That is one thing I got here throughout whereas engaged on this venture

In transactional datasets, it’s widespread to see:

Many shoppers with the identical Frequency (e.g. one-time patrons)
Extremely skewed Financial values
Small samples the place quantile binning can fail

To maintain issues sturdy and readable, we’ll wrap the scoring logic in a small helper perform.

def rfm_score(collection, ascending=True, n_bins=5):
# Rank the values to make sure uniqueness
ranked = collection.rank(methodology=’first’, ascending=ascending)

# Use pd.qcut on the ranks to assign bins
return pd.qcut(
ranked,
q=n_bins,
labels=vary(1, n_bins+1)
).astype(int)

To elucidate what’s occurring right here:

We’re making a helper perform that turns a uncooked numeric column right into a clear RFM rating utilizing quantile-based binning.
First, the values are ranked. So, as a substitute of binning the uncooked values instantly, we rank them first. This step ensures distinctive ordering, even when many shoppers share the identical worth (a standard problem in RFM knowledge).
The ascending flag lets us flip the logic relying on the metric — for instance, decrease recency is best, whereas increased frequency and financial values are higher.
Subsequent, we’re making use of quantile-based binning. qcut splits the ranked values into n_bins equally sized teams. Every buyer is assigned a rating from 1 to five (by default), the place the rating represents their relative place inside the distribution.
Lastly, the outcomes will likely be transformed to integers for straightforward use in evaluation and segmentation.

In brief, this perform offers a sturdy and reusable means to attain RFM metrics with out operating into duplicate bin edge errors — and with out overcomplicating the logic.

Step 2: Making use of the Scores

Now we are able to rating every metric cleanly and constantly:

# Assign R, F, M scores
rfm['R_Score'] = rfm_score(rfm['Recency'], ascending=False) # Current purchases = excessive rating
rfm['F_Score'] = rfm_score(rfm['Frequency']) # Extra frequent = excessive rating
rfm['M_Score'] = rfm_score(rfm['Monetary']) # Greater spend = excessive rating

The one particular case right here is Recency:

Decrease values imply more moderen exercise
So we reverse the rating with ascending=False
Every little thing else follows the pure “increased is best” rule.

What This Means for NovaShop

As a substitute of seeing this:

Recency = 326
Frequency = 1
Financial = 77,183.60

NovaShop now sees one thing like:

R = 1, F = 1, M = 5

That’s immediately extra interpretable:

Not latest
Not frequent
Excessive spender (traditionally)

Step 3: Making a Mixed RFM Rating

Now we mix these three scores right into a single RFM code:

rfm['RFM_Score'] = (
rfm['R_Score'].astype(str) +
rfm['F_Score'].astype(str) +
rfm['M_Score'].astype(str)
)

This produces values like:

555 → Finest prospects
155 → Excessive spenders who haven’t returned
111 → Clients who’re doubtless gone

Every buyer now carries a compact behavioral fingerprint. And we’re not achieved but.

Translating RFM Scores Into Buyer Segments

Uncooked scores are good, however let’s be sincere: no advertising and marketing supervisor needs to have a look at 555, 154, or 311 all day.

NovaShop wants labels that make sense at a look. That’s the place RFM segments are available.

Step 1: Defining Segments

Utilizing RFM scores, we are able to classify prospects into significant classes. Right here’s a standard method:

Champions: High Recency, prime Frequency, prime Financial (555) — your greatest prospects
Loyal Clients: Common patrons, will not be spending probably the most, however hold coming again
Massive Spenders: Excessive Financial, however not essentially latest or frequent
At-Threat: Used to purchase, however haven’t returned just lately
Misplaced: Low scores in all three metrics — doubtless disengaged
Promising / New: Current prospects with decrease frequency or financial spend

This transforms summary numbers right into a narrative that advertising and marketing and administration can act on.

Step 2: Mapping Scores to Segments

Right here’s an instance utilizing easy conditional logic:

def rfm_segment(row):
if row['R_Score'] >= 4 and row['F_Score'] >= 4 and row['M_Score'] >= 4:
return 'Champions'
elif row['F_Score'] >= 4:
return 'Loyal Clients'
elif row['M_Score'] >= 4:
return 'Massive Spenders'
elif row['R_Score'] <= 2:
return 'At-Threat'
else:
return 'Others'
rfm['Segment'] = rfm.apply(rfm_segment, axis=1)

Now every buyer has a human-readable label, making it instantly actionable.

Let’s evaluation our outcomes utilizing rfm.head()

Step 3: Turning Segments into Technique

With labeled segments, NovaShop can:

Reward Champions → Unique offers, loyalty factors
Re-engage Massive Spenders & At-Threat prospects → Customized emails or reductions
Focus advertising and marketing correctly → Don’t waste effort on prospects who’re really misplaced

That is the second the place knowledge turns into technique.

What NovaShop Ought to Do Subsequent (Key Takeaways & Suggestions)

In the beginning of this evaluation, NovaShop had a well-recognized drawback:
Loads of transactional knowledge, however restricted readability on buyer behaviour.

By making use of the RFM framework, we’ve turned uncooked buy historical past into a transparent, structured view of who NovaShop’s prospects are — and the way they behave.

Now let’s discuss what to truly do with it.

1. Shield and Reward Your Finest Clients

Champions and Loyal Clients are already doing what each enterprise needs:

They purchase just lately
They purchase usually
They generate constant income

These prospects don’t want heavy reductions — they want recognition.

Beneficial actions:

Early entry to gross sales
Loyalty factors or VIP tiers
Customized thank-you emails

The aim right here isn’t acquisition, it’s retention.

2. Re-Interact Excessive-Worth Clients Earlier than They’re Misplaced

Essentially the most harmful phase for NovaShop isn’t “Misplaced” prospects.
It’s At-Threat and Massive Spenders.

These prospects:

Have proven clear worth prior to now
However haven’t bought just lately
Are one step away from churning utterly

Beneficial actions:

Focused win-back campaigns
Customized affords (not blanket reductions)
Reminder emails tied to previous buy conduct

Profitable again an current buyer is sort of at all times cheaper than buying a brand new one.

3. Don’t Over-Spend money on Actually Misplaced Clients

Some prospects will inevitably churn. RFM helps NovaShop determine these prospects early and keep away from spending advert finances, reductions and advertising and marketing effort on customers who’re unlikely to return. This isn’t about being chilly — it’s about being environment friendly.

4. Use RFM as a Dwelling Framework, Not a One-Off Evaluation

The true energy of RFM comes when it’s:

Recomputed month-to-month or quarterly
Built-in into dashboards
Used to trace motion between segments over time

For NovaShop, this implies asking questions like:

What number of At-Threat prospects turned Loyal this month?
Are Champions rising or shrinking?
Which campaigns truly transfer prospects up the ladder?

RFM turns buyer behaviour into one thing measurable and trackable.

Closing Ideas: Closing the EDA in Public Collection

Once I began this EDA in Public collection, I wasn’t making an attempt to construct the proper evaluation or show superior methods. I needed to decelerate and share how I truly suppose when working with actual knowledge. Not the polished model, however the messy, iterative course of that often stays hidden.

This venture started with a loud CSV and plenty of open questions. Alongside the way in which, there have been small points that solely surfaced as soon as I paid nearer consideration — dates saved as strings, assumptions that didn’t fairly maintain up, metrics that wanted context earlier than they made sense. Working by means of these moments in public was uncomfortable at instances, but additionally genuinely beneficial. Every correction made the evaluation stronger and extra sincere.

One factor this course of bolstered for me is that the majority significant insights don’t come from complexity. They arrive from slowing down, structuring the information correctly, and asking higher questions. By the point I reached the RFM evaluation, the worth wasn’t within the formulation themselves — it was in what they compelled me to confront. A buyer who spent lots as soon as isn’t essentially beneficial at this time. Recency issues. Frequency issues. And none of those metrics imply a lot in isolation.

Ending the collection with RFM felt deliberate. It sits on the level the place technical work meets enterprise considering, the place tables flip into conversations and numbers flip into selections. It’s additionally the place exploratory evaluation stops being purely descriptive and begins changing into sensible. At that stage, the aim is not simply to know the information, however to determine what to do subsequent.

Doing this work in public modified how I method evaluation. Writing issues out compelled me to elucidate my reasoning, query my assumptions, and be comfy displaying imperfect work. It jogged my memory that EDA isn’t a guidelines you rush by means of — it’s a dialogue with the information. Sharing that dialogue makes you extra considerate and extra accountable.

This can be the ultimate a part of the EDA in Public collection, however it doesn’t really feel like an endpoint. Every little thing right here might evolve into dashboards, automated pipelines, or deeper buyer evaluation.

And when you’re a founder, analyst, or crew working with buyer or gross sales knowledge and making an attempt to make sense of it, this sort of exploratory work is usually the place the most important readability comes from. These are precisely the sorts of issues I take pleasure in working by means of — slowly, thoughtfully, and with the enterprise context in thoughts.

For those who’re documenting your personal analyses, I’d like to see the way you method it. And when you’re wrestling with related questions in your knowledge and wish to speak by means of them, be at liberty to achieve out on any of the platforms beneath. Good knowledge conversations often begin there.

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