Keynote Resources
Subtract to Ship
The problem is addition.
You just watched the talk. Here is everything you need to run the method Monday morning.
The Method
1. Find
Your customers cannot tell you what they want. Watch what they do. Analytics over opinions. Forty-five spaghetti sauces and a spoon.
2. Cut
For every proposed addition, first ask what you can remove. The Instagram question: if you could keep only one feature — which one? That answer is your product. Everything else is fear dressed up as strategy.
3. Ship
Marshmallow on top first. Ship ugly, ship incomplete, ship to ten users this week. Then iterate. Prototype before you plan. The kindergartners beat the business students because they tested before they theorised.
The 60-Second Subtraction Audit
The exercise from the talk. Run it in your next team meeting.
- 1. Open your notes app. (10 sec)
- 2. Write down the one feature, process, meeting, or report everyone complains about but nobody kills. (60 sec)
- 3. Share with your neighbor. Pick the more ridiculous one. (30 sec)
- 4. Kill the top one this week. Not next quarter. This week.
Before You Cut
The 20/20 Cut Filter
Fewer than 20% use it. Fewer than 20% would cancel without it. → Cut candidate. (Felix's working heuristic from product practice — a rule of thumb, not research.)
The Circuit City Rule
Subtraction wins when you remove what the customer never valued. It fails when you remove the invisible thing that makes the rest work. Circuit City fired its most experienced salespeople to save $45M a year — and filed for bankruptcy twenty months later.
“Keep Three” Too Scary? The Starter Cut
Keep the 3 features that drive 80% of engagement. Build the next sprint on those alone. Watch retention.
Sources
Every external claim in the talk, with its citation and its caveat. Where a number is contested or secondhand, the note says so.
Adams, G. S., Converse, B. A., Hales, A. H., & Klotz, L. E. (2021). “People systematically overlook subtractive changes.” Nature, 592, 258–261. nature.com
Eight experiments. The additive default deepens under cognitive load; explicit cueing increases subtraction — the cue helps, it doesn't cure. Replicated (Fillon et al. 2025, Journal of Creative Behavior; Juvrud et al. 2024, Scientific Reports), with effect size varying by task and culture.
Mehta, R., & Zhu, M. (2016). “Creating When You Have Less: The Impact of Resource Scarcity on Product Use Creativity.” Journal of Consumer Research, 42(5), 767–782. doi.org
Six experiments. Scarcity salience produces more novel product-use solutions.
Thompson, D. V., Hamilton, R. W., & Rust, R. T. (2005). “Feature Fatigue: When Product Capabilities Become Too Much of a Good Thing.” Journal of Marketing Research, 42(4), 431–442.
Pre-purchase, consumers overweight capability; post-use, usability dominates. Consumers choose feature-loaded products that lower their own satisfaction.
Norton, M. I., Mochon, D., & Ariely, D. (2012). “The IKEA Effect: When Labor Leads to Love.” Journal of Consumer Psychology, 22(3), 453–460.
Self-assemblers bid roughly 63% more for identical products. Why cutting your own work hurts.
CB Insights. “The Top Reasons Startups Fail” (2014 post-mortem analysis; 2024 update). cbinsights.com
Caveat, as spoken on stage: self-reported post-mortems — founders who fail are not always the most reliable narrators of why. Not peer-reviewed. “Ran out of capital” is how a startup dies, not why.
Instagram / Burbn: Systrom, K. — interviews and Quora answers, 2010–2011. theatlantic.com
Launch October 6, 2010; ~25,000 users in the first 24 hours (founder-reported, widely corroborated); acquired ~18 months later.
McDonald brothers / Speedee Service System, 1948: Love, J. (1986). McDonald's: Behind the Arches. Bantam.
Closed a successful drive-in for three months; cut roughly two-thirds of the menu down to the nine items order slips showed people actually bought; wait times fell from ~30 minutes to ~30 seconds.
Jaipur Foot: developed 1968 by P. K. Sethi and Ram Chandra Sharma. jaipurfoot.org
~US$45 prosthetic designed for barefoot use, squatting, cross-legged sitting. 1.8M+ fitted via BMVSS.
LEGO turnaround: Robertson, D. (2013). Brick by Brick; LEGO Group annual reports 2003–2014.
2003: net loss DKK 1.4bn. Unique components cut roughly in half (~13,000 → ~7,000). Revenues quadrupled 2004–2014; passed Mattel as the world's largest toy company by revenue in 2014.
Moskowitz / spaghetti sauce: Gladwell, M. (2004). TED talk; What the Dog Saw (2009). ted.com
Caveat, as spoken on stage: the $600M figure is Gladwell's telling, not Campbell's accountants'. The segmentation work itself (45 varieties, early eighties) is real.
Marshmallow Challenge: invented by Peter Skillman (TED 2006); popularized by Tom Wujec (TED 2010). ted.com
Caveat, as spoken on stage: workshop data, never peer-reviewed — a parable with a tally sheet, not a study. Reported averages: business students ~10 inches, kindergartners ~26.
Circuit City: contemporaneous coverage, March 2007 (e.g., The New York Times); SEC filings; Chapter 11, November 10, 2008.
~3,400 of the most experienced salespeople dismissed to save ~$45M/year. The causal reading is the standard business-press analysis of the collapse.
B-17 / the first pilot's checklist: Gawande, A. (2009). The Checklist Manifesto, ch. 2; FAA history (Schamel, “How the Pilot's Checklist Came About”).
Boeing Model 299 crash, October 30, 1935. The one-page checklist followed; the first group of aircraft then flew ~1.8 million miles without a serious accident.
Everything on this page as a printable A4 PDF — the method, the exercises, and every source.
Print versions of the field card and templates: email felix@vulpine-industries.com and name the talk.
Live version with clickable links: https://felixlenhard.com/subtract/
The Book
Subtract to Ship
A four-volume methodology. Publishing 2026.
Twenty years of building automation systems for European industrial groups. Five years coaching 50+ startups. Twelve products shipped to 50+ countries. The method behind all of it — documented, cited, and structured so you can run it on your own product, team, or company. Volume I: Find. Volume II: Cut. Volume III: Ship. Volume IV: The Subtraction Organisation.
About the BooksBook Felix for Your Event
Keynotes (20–45 min). Workshops (half-day). Post-talk office hours. Available in English and German. Based in Graz, Austria — available internationally.