Table 11 Sept 2026From “The 20-55 rule: customer prioritization misclassifies the portfolio”

Why do historically predicted customer tiers fail to match future profitability cohorts?

Table 1Why do historically predicted customer tiers fail to match future profitability cohorts?

Object	Question	Mistake if it is collapsed
Predicted group	Who does the model select at the decision date?	A forecast is treated as an observed outcome.
Future group	Who belongs to the value group after the stated horizon?	The result is read without its time boundary.
False exclusion	Who later belongs in the target group but was not selected?	Missed opportunity is hidden.
False inclusion	Who is selected but later belongs outside the target group?	Treatment cost is hidden.
Profitability object	What value, cost, price, and margin inputs are being aggregated?	Revenue or activity is treated as profit.

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Source: Table from this essay. Sources and interpretation are given in the article.

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From the essay

Growth that compounds

The 20-55 rule: customer prioritization misclassifies the portfolio

A customer ranking can miss future top customers: keep prediction horizon, cutoff, misclassification cost, and profitability inputs visible.

1 Sept 2026

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APA 7

Isoglu, S. (2026). Why do historically predicted customer tiers fail to match future profitability cohorts? [Table]. isoglu.com. https://isoglu.com/insights/exhibits/isoglu-2026-the-20-55-rule-customer-prioritization-misclassifies-the-portfolio-fig01/

BibTeX

@misc{isoglu-2026-the-20-55-rule-customer-prioritization-misclassifies-the-portfolio-fig01,
  author = {Isoglu, Sinan},
  title = {{Why do historically predicted customer tiers fail to match future profitability cohorts?}},
  year = {2026},
  howpublished = {Table 1, isoglu.com},
  url = {https://isoglu.com/insights/exhibits/isoglu-2026-the-20-55-rule-customer-prioritization-misclassifies-the-portfolio-fig01/},
  note = {From the essay {The 20-55 rule: customer prioritization misclassifies the portfolio}}
}

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  <figcaption>Table 1: Why do historically predicted customer tiers fail to match future profitability cohorts?. Source: Table from this essay. Sources and interpretation are given in the article. <a href="https://isoglu.com/insights/exhibits/isoglu-2026-the-20-55-rule-customer-prioritization-misclassifies-the-portfolio-fig01/">View exhibit</a>.</figcaption>
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