A Swarbrick Jones meta-study of ~2,600 ecommerce experiments ranked 28 persuasion levers by average sales effect. Volume scarcity ('only a few left') came first, social proof ('lots of people bought this') second, and time scarcity/urgency third — making scarcity the first thing an ecommerce brand should test.

~2,600 ecommerce studies, many in travel, across 28 levers
#1: volume scarcity — limited stock remaining
#2: social proof — popularity signals
#3: time scarcity / urgency — limited time to act
Charity vs commercial contexts don't always transfer

“Of the 28 they look at, the most effective overall is volume scarcity. There aren't many of these hotel rooms left. Next is social proof.”
Richard Shotton

#ecommerce#scarcity#social-proof#conversion

Explainer

Goodhart's Law: when a metric becomes a target it stops being useful

Optimising exclusively for a proxy metric like email subscribers detaches you from the real outcome — engaged people who value your emails. Williamson illustrates with an absurd 'sign up and get a million pounds' offer that would hit the subscriber target while destroying the underlying goal. Any gap between what you incentivise and what you want produces dangerous repercussions.

A metric used as a target loses its validity
Optimising a proxy can diverge sharply from the real goal
Even a sliver of gap between incentive and intent creates problems
Gneezy's Mixed Signals covers responses to ill-set incentives

“Once a metric is used as a target, that metric loses all validity.”
Chris Williamson

“If there was a sliver of difference between what you're incentivizing and what you actually want, you generate some pretty dangerous repercussions.”
Richard Shotton

#metrics#incentives#goodharts-law#strategy

Explainer

Present preference bias: give lots of notice before a price rise

Liam Delaney's research found ~60% of people would rather pay £16 in a month than £13 now — an implied annual interest rate over 1,000% — because we massively overweight pain in the present. The practical lesson: push price rises far into the future (two or three months' notice) so the cost feels distant and less aggravating.

People prefer paying more later to less now
Implied annual interest rate exceeds 1,000%
We overweight present pleasure and pain, discount the future
Announce price rises with long notice, not immediately

“We overweight pleasure and the pain in the now, and we discount pleasure and pain in the future far, far too much.”
Richard Shotton

#pricing#present-bias#time-discounting#behavioural-science

Explainer

Authoritarian messages backfire more when they come from power

Pennebaker found a 'do not graffiti!!' sign drew twice the graffiti of a polite one — but the backfire was far stronger when the sign came from the head of security rather than the groundsman. Reactance is amplified by the sender's authority, which Williamson links to ancestral dominance-versus-prestige leadership: dominant leaders are tolerated in war but resented in peacetime.

Authoritarian phrasing roughly doubled the unwanted behaviour
Backfire scaled with the sender's perceived authority
Peer-to-peer requests trigger less reactance than power-laden ones
Dominance leaders suit warfare; prestige leaders suit peacetime

“Reactance is far more likely to occur if the message comes from someone in a position of power.”
Richard Shotton

#reactance#authority#leadership#evolutionary-psychology

Story· 3

Story

Ogilvy's charity test: thick paper doubled donations, urgency backfired

Ogilvy Change tested seven messages across 1.2 million Christian Aid donation envelopes. Heavier, more expensive paper stock generated twice the donations (39p vs 18p average), while scarcity/urgency messaging that works in ecommerce actually decreased donations below the control — a caution that tactics don't transfer across contexts.

1.2M envelopes, seven different message variants tested
Thicker paper stock doubled average donations (39p vs 18p)
'One week to donate' urgency decreased giving vs control
Ogilvy publishes failures as well as successes
Commercial scarcity tactics don't always work for charity

“That thicker paper generated twice the level of donations... 39 pence on average per person versus 18 pence for the gift aid offering.”
Richard Shotton

#charity#testing#scarcity#advertising

Story

Paid per fossil piece, peasants smashed whole bones into twenty

From Gneezy's Mixed Signals: 19th-century archaeologists in China paid locals a set fee per fossil fragment. To maximise income, people smashed complete fossil bones into around twenty pieces and delivered them one at a time — a vivid warning about designing incentives that reward the wrong behaviour.

Reward was per fossil piece, not per complete fossil
People broke whole bones into ~20 fragments to maximise pay
Classic example of an incentive backfiring
Be careful what behaviour your incentive actually rewards

“Rather than bring a complete fossil bone... they smash them into 20 pieces, and they take each piece one at a time to the archaeologist…”
Richard Shotton

#incentives#unintended-consequences#behavioural-science

Story

90% called COVID toilet-roll price hikes unfair — economics be damned

Shotton's COVID-era study asked whether doubling the price of scarce toilet roll was fair; around 90% said unfair. Economists frame it as supply and demand, but people see exploiting a demand surge as a fairness violation and may punish the seller — echoing Frans de Waal's capuchin monkeys who refuse cucumber once they see a peer paid in grapes.

~90% judged pandemic price rises very unfair
Economists call it normal supply and demand
People punish perceived exploitation of scarcity
De Waal's monkeys reject unequal pay — a shared evolutionary drive

“People feel that the exploitation of a surge in demand with excess pricing is unfair, and there's a danger that they will punish that supplier.”
Richard Shotton

#fairness#pricing#covid#behavioural-economics

Tool· 3

Tool

Why stacking discounts (40% + 10% + 5%) beats one big number

Retailers like TK Maxx display layered discounts — 40% off plus 10% plus 5% — because shoppers naively add them to 55%. In reality each successive cut comes off a smaller base, so the true saving is around 51%. The tactic exploits denominator neglect to make an offer feel larger than it is.

People mentally sum stacked discounts (40+10+5 = 55%)
Each discount actually applies to a progressively smaller number
The real total is lower (~51%) than the perceived total
Stacking makes buyers feel they're getting more than they are

“40, 10, 5, that's 55% off. But it's not actually because if you take off 40, your 10 is then off a smaller number... it's…”
Richard Shotton

#pricing#discounts#denominator-neglect#retail

Tool

Font size trick: shrink the sale price to make the discount feel bigger

In a Coulter brothers study, shoppers who saw the discounted price in a smaller font than the original perceived a larger price reduction, because people conflate a number's physical size with its value. Shotton flags it as a single-study finding — worth testing cheaply, but not as robust as scarcity or social proof.

Small font on the sale price signals a bigger reduction
People conflate physical size of a number with what it represents
It's a one-off study, weaker evidence than meta-analysed effects
Cheap to A/B test on your own pricing with potential margin upside

“The people who see the end discounted price in the smaller font, they think there's been a larger reduction in price.”
Richard Shotton

#pricing#typography#perception#testing

Tool

Write copy at a lower reading age (and use the Hemingway app)

Small friction has an outsized effect on attention, so copy — especially YouTube thumbnails — should be pitched at a much lower reading age than you'd expect. The free Hemingway app scores your reading age in real time and flags passive voice and long sentences, letting you simplify as you write.

Every millisecond of scrolling attention is precious
Convey the message faster and simpler than the next option to win clicks
Hemingway app gives a live reading-age score
It flags passive voice, long and complex sentences

“One of the simplest things you can do is pitch at a much lower reading age than you expect. It will help.”
Richard Shotton

#copywriting#readability#youtube#tools

Takeaway· 2

Takeaway

The story you tell yourself determines how an experience feels

Sam Harris notes a post-workout state — sweating, pounding heart, metallic taste — is objectively uncomfortable yet enjoyable purely because of its framing; feel it stuck in traffic and you'd call an ambulance. Framing isn't only a marketing tool: reinterpreting the same bodily signals changes the lived experience, as with Shotton reframing flight adrenaline via heavy-metal music.

Identical physical sensations feel good or terrifying by context
A post-workout body state would trigger panic in traffic
The narrative around an experience shapes the experience itself
Reframing is a personal-development lever, not just a commercial one

“Our story of what we tell ourselves around an experience very much is the determinant of the experience as well.”
Chris Williamson

#framing#mindset#self-talk#psychology

Takeaway

The publicity principle: would customers be angry if they knew?

Drawing on philosopher John Rawls, Shotton offers a moral test for pricing and persuasion tactics: if a customer knew you were applying this tactic, would they be angry? If so, it should set off alarm bells. Short-term gains from nefarious tactics risk long-term retribution once people feel manipulated too far.

Rawls's publicity principle as an ethics check for marketers
Ask whether disclosure would anger the customer
Short-term cash gains can trigger long-term backlash
Balance how hard you push manipulative pricing tactics

“If someone knew you were applying this tactic, would they be angry with you? And if they are, then it should set off some alarm…”
Richard Shotton

#ethics#persuasion#manipulation#philosophy

Frameworks in this episode

Extremeness Aversion (Decoy Pricing)

Monadic Testing (The Need to Experiment)

The 'But You Are Free' Principle

The Fairness Principle

The Foot-in-the-Door Technique

The Framing Effect

The Halo Effect

The Labour Illusion

The Peak-End Rule

The Red Sneakers Effect

The Rule of 100

Insights & moments

✶Explainer· 4

The most powerful ecommerce lever: volume scarcity beats social proof

Goodhart's Law: when a metric becomes a target it stops being useful

Present preference bias: give lots of notice before a price rise

Authoritarian messages backfire more when they come from power

❝Story· 3

Ogilvy's charity test: thick paper doubled donations, urgency backfired

Paid per fossil piece, peasants smashed whole bones into twenty

90% called COVID toilet-roll price hikes unfair — economics be damned

✦Tool· 3

Why stacking discounts (40% + 10% + 5%) beats one big number

Font size trick: shrink the sale price to make the discount feel bigger

Write copy at a lower reading age (and use the Hemingway app)

▲Takeaway· 2

The story you tell yourself determines how an experience feels

The publicity principle: would customers be angry if they knew?

Explainer· 4

Story· 3

Tool· 3

Takeaway· 2