Hey it’s Idris from Retentiononly.
Most email campaigns fail for one reason.
They don't move people emotionally.
The brands printing money in email aren't writing better. They're writing with psychology.
7 principles, specifically.
Stack them correctly and you can rebuild every campaign your brand sends, without adding a single email to the calendar.
Prefer to watch instead of read? I break down each one with screenshots and real numbers here: https://youtu.be/36Yn6DZIZuQ
Otherwise, here are all 7.
1. Scarcity → 258% revenue uplift
Sent a "Sold out 3 years in a row" campaign for a coffee brand. No discount. No promotion. Just scarcity.
£13,500 in one send. 41.3% above their average.
Same play for a skincare brand: $11,000 vs their normal $3,000.
Example
Why it works: When something feels rare, people want it more. Shrinking availability signals worth.
What to do:
"Small batch" or "limited release"
"Only X left in stock"
"May sell out today"
"Back in stock"
Scarcity raises perceived value, without touching the price.
2. Urgency → Last email beat every email before it
Easter sale. 6 emails sent. The 7th and final one outperformed all 6.
Why? We maxed urgency: either you buy today and save 55%, or you pay full price tomorrow.
Example
Why it works: Urgency forces a decision. Without it, "I'll think about it" wins every time.
What to do:
Use "either/or" framing
Add countdown timers
"Ends tonight" subject lines
Stack with fear of missing out
Don't just convince them. Move them.
Two probiotic campaigns leading with "1,600+ reviews" and real customer photos. Each one did €4,600 vs the normal €3,000.
Example
Why it works: Uncertainty is the #1 reason people don't buy. Proof removes it.
What to do:
Lead with the review count in the hero image
Show real customer photos (UGC > stock)
Place testimonials next to your CTA
Add live counters ("1,247 sold this week")
People follow the crowd. Show them there's a crowd.
Added an influencer endorsement to a client's campaign. €1,886 absolute uplift.
This is exactly why IM8 leads with "Official partner of Inter Miami CF." If Messi, Suarez, and Beckham endorse the brand, skepticism evaporates.
Example
Why it works: People defer to expertise — especially in health, wellness, and high-consideration categories.
What to do:
Expert endorsements
Media mentions (Forbes, Men's Health)
Certifications and awards
Founder credentials
Visual cues (lab shots, white coats)
Authority shortcuts skepticism.
5. Reciprocity → 223% uplift
Ran a "credit sale" framed entirely as a gift. Two emails. €12,000 each. Their normal campaign? €2-8K.
Example
Why it works: When you give first, people feel they owe you back. That feeling gets paid at checkout.
What to do:
Reframe "15% off" as "We're gifting you 15%"
Use the word free every time you can
Send pure-value emails before the pitch
Position discounts as gifts, not promotions
Same numbers. Different psychology. Wildly different conversion.
6. Liking → 184% uplift
Wrote founder emails in the founder's actual voice, talking about the actual problem he had. Two emails: €21,000 and €17,000. Their average campaign? €6,500.
Duradry does this perfectly. Their founder email opens with: "For years, Jack, our founder, suffered the pain and embarrassment of excessive sweating. He was drenched all day, every day."
The reader thinks: he had my problem, he solved it, he can probably help me too.
Example
Why it works: People don't buy from brands. They buy from people they relate to.
What to do:
Plain text. Skip the branded HTML.
Write in the founder's voice
Open with the customer's exact problem
Share real struggles, not polished bios
Connection converts.
7. Anchoring → 154% uplift (my favorite)
Showed a $229.50 anchor first. Then revealed the offer at $74.25. Even broke it down to $2.47 per shot.
Two emails: $10,000 and $8,800. Their average? Around $3,000.
Example
Why it works: People don't judge prices in absolute terms — they compare. Drop a higher number first, and everything after feels cheap.
What to do:
Always show the strikethrough price first
State the savings explicitly ("You save $77.97")
Bundle products with a clear "total value" anchor
Break the price into per-day or per-use cost
Anchoring sells the offer before the copy even starts.
Here's the catch.
Knowing these 7 doesn't move the needle.
Applying them correctly across every campaign, flow, promotion, and launch does.
That's where almost every brand leaves six figures on the table every year.
If your brand is doing at least $100K/month and you want me to personally audit your Klaviyo and show you which of the 7 you're missing and exactly how much revenue we could pull from your existing list without spending a cent more on ads, then book a free audit here: [BOOK YOUR FREE AUDIT]
If a call is too much commitment right now, watch the full breakdown first. Every email, every number, every framework: https://youtu.be/36Yn6DZIZuQ
Talk soon,
Idris