Arnold Petersen

Arnold Petersen is a product designer and researcher based in Cape Town, and the publisher of Sly by Design.

He has spent more than two decades designing digital products — over a hundred shipped applications with tens of millions of combined downloads — much of that career inside South African financial services, leading design teams responsible for the banking, insurance, and rewards experiences of precisely the kind this registry documents. That experience is the reason this site exists: the mechanics catalogued here are ones a designer spends years building before concluding they deserve documenting instead.

Outside financial services, he has photographed South Africa for more than 25 years and has produced and published two photography books under his GeoParallax imprint — Edge of the Continent: The Western Cape and, with Dr. Ian Kennedy, Cape Town: A Distinct Travel Guide — work that shaped the evidence-first, end-to-end approach this registry runs on. Sly by Design forms part of his longer-term research programme into deceptive design in financial services in the Global South.

The site is self-funded and independent: no advertising, no affiliate links, and no funding from any institution documented in the registry. Every entry and essay is produced under a stated methodology — archived documents captured on dated snapshots, verbatim quotes with page references, numbered dataset records, and a standing corrections policy reachable at corrections@slybydesign.com. The registry describes what the documents say; it does not speculate about intent, and it does not make legal findings.

More about the project on the About page.

Posted by this author

A currency that isn't one: what the documents say Discovery Miles are

Arnold Petersen
Date : 24 Jul, 2026
Categories : Registry analysis
Tags : Discovery Discovery miles Unilateral change Forfeiture Estate

The cover of Discovery's current Discovery Miles brochure introduces the product in seven words: "Our rewards currency that's more valuable than cash" (DISCOVERY MILES brochure, reference-code date 2

deceptive service level contract with stacking services

Organised by combination: how the rules are published, and what that structure shows

Arnold Petersen
Date : 24 Jul, 2026
Categories : Registry analysis
Tags : Discovery Product rules Cross product gating Documentation

Discovery does not publish one set of Vitality rules per programme. Its product-rules page (discovery.co.za/vitality/product-rules, captured 21–23 July 2026) is organised into five product-combination

lock-in mechanism, a deliberate architecture

The lock-in evolved: from contract terms to economic architecture

Arnold Petersen
Date : 25 Jul, 2026
Categories : Registry analysis
Tags : Discovery Lock in Unilateral change Forfeiture Cross product gating

In 2018, a Discovery Card holder who wanted out of the Discovery Miles benefit faced a sentence any consumer lawyer would recognise: "You may request cancellation of the Discovery Miles benefit, but i

What happens to your Discovery Miles when you leave

Arnold Petersen
Date : 24 Jul, 2026
Categories : Registry analysis
Tags : Discovery Discovery miles Forfeiture Consumer explainer

If you hold Discovery Miles, the rules for losing them live mainly on two pages of the current Discovery Miles terms and conditions — the document dated 1 July 2026, captured by this registry on 21 Ju

Use it or lose it: how Vitality Fitness benefits expire

Arnold Petersen
Date : 27 Jul, 2026
Categories : Registry analysis
Tags : Discovery Vitality fitness Vitality money Forfeiture Consumer explainer

If you use Vitality Fitness, several of the things it gives you come with an expiry date. The rules live in one document — the "Vitality Fitness terms and conditions" benefit guide (`vitality-fitness.