[nasserboan]

Type

• Bug fix
• Feature
• Docs
• Breaking change

Related issue

None

What changed

The landing page's parameter table stopped at naming the four numbers. It now
explains them: a reading of each pair as a distribution (purchase rates as
Gamma, dropout probabilities as Beta), the derived quantities that carry
business meaning (r/α, about 0.055 repeat purchases a week on CDNOW;
a/(a+b), a 25% average chance of quitting per repeat purchase), and a density
figure showing both averages sitting well right of the pile — the average
customer is not the typical customer. Also fixes the table's α label, which
read "Gamma scale" while the mean it sits next to is r/α, and scopes the
dropout row to repeat purchases, matching the model. Version bumps to 0.2.1;
no library code changes.

How it was tested

Docs build clean with -W (warnings as errors). Full suite unchanged and
green: 292 passed, 1 skipped. The figure is generated from the published
parameter values analytically, no simulation.

Checks

• uv run pytest
• uv run ruff check
• uv run ruff format --check
• Notebooks still execute (uv run pytest --nbmake examples/)
• Docs updated
• Title reads as the commit message it will become