Some phrases roll off the tongue so easily that we never stop to think where they came from.
“Read between the lines” is one of them. We use it to mean spotting what isn’t said — sensing the hidden message beneath polite words or formal writing.
It’s the kind of skill every good marketer — and every married person — learns eventually.
But the phrase has a fascinating literal history that takes us back to the secret world of 18th-century spies, invisible ink, and a kind of creativity that would make even modern AI blush.
The Hidden Message
Long before we had encrypted emails or password-protected PDFs, people sent secret messages in letters written with invisible ink. The spy or lover would write an innocent message first, then use a special solution — often lemon juice, milk, or vinegar — to add the real message between the lines.
To read it, the recipient would heat the letter gently by candle flame or treat it with certain chemicals, revealing the hidden words in brownish ink. Hence, to “read between the lines” literally meant finding the concealed message lurking in the blank spaces.
That practice became particularly popular during the 18th and early 19th centuries — times of war, diplomacy, and romantic intrigue. Some of the letters uncovered by historians still bear scorch marks from people holding them a bit too close to the flame in their eagerness to uncover the truth.
So next time someone says “read between the lines,” you can imagine them with a candle in one hand, hoping the paper doesn’t catch fire before the secret’s revealed.
From Espionage to Everyday English
As the literal practice of invisible writing faded, the phrase survived — turning metaphorical.
By the mid-1800s, “reading between the lines” meant grasping the subtext — the unspoken meaning behind words that look perfectly harmless on the surface.
You’ll recognise the type:
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“That’s an interesting idea,” said through gritted teeth.
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“You’re brave to try that colour,” murmured at the hairdresser’s.
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Or my personal favourite: “Let’s circle back to that later.” (Translation: Let’s never mention this again.)
Whether in social conversation, politics, or business, most of life’s real communication happens in the gaps — and learning to read between those gaps is a priceless skill.
Reading Between the Lines in Dentistry and Marketing
In my years as a dentist, I became rather good at reading between the lines. Patients rarely said what they really meant.
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“It doesn’t hurt much” = “It hurts a lot but I’m pretending to be brave.”
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“I only want what’s necessary” = “Please make it look perfect but don’t mention the cost.”
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“I hate needles” = “I hate needles.” (That one, at least, was usually true.)
When I moved into online marketing, I realised the same principle applies — only this time it’s about understanding customers, not cavities.
Prospects don’t always say, “I’m scared of wasting money” or “I don’t understand how this works.” But you can feel it in their hesitation, their questions, or the way they read your sales page three times before clicking anything.
That’s why the best marketers listen carefully — not just to what’s said, but to what’s meant.
How This Helps in Affiliate Marketing
In affiliate marketing, reading between the lines means anticipating the doubts your audience never voices. It means answering their real questions before they even think to ask them.
When you write an email, for example, your reader might be silently asking:
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“Does this really work for someone like me?”
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“Is this another over-hyped promise?”
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“How much time will this take?”
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“What if I fail?”
Address those unspoken fears — clearly, calmly, confidently — and you’ll build trust faster than any flashy headline could.
That’s why my recent posts and eBooks often focus on stories, not sales talk.
A story builds connection.
A connection builds trust.
And trust turns readers into buyers.
You could say the most successful marketers aren’t just writers — they’re translators of human emotion.
Between the Lines of Life
There’s another side to this phrase that I’ve come to appreciate more with age.
Reading between the lines isn’t just about detecting hidden meaning — it’s about paying attention.
It’s about noticing what’s not said in a conversation, a friendship, or even your own goals. The tone, the pauses, the small hesitations — they reveal more than the words ever do.
When I look back, the biggest opportunities in my own life weren’t always written in bold type. They were in the margins — subtle hints that appeared when I stopped chasing perfection and started noticing patterns.
In online business, that might be the small idea that keeps resurfacing, the message that resonates most with your readers, or the product that quietly outperforms everything else. It’s all there, between the lines — if you’re paying attention.
The Marketer’s Candle
So perhaps “reading between the lines” today is our modern equivalent of holding a letter to the candlelight.
We shine a bit of warmth, focus, and curiosity onto the blank spaces — and suddenly, the truth glows through.
When I write emails or create training modules now, I ask myself:
“What’s my reader really thinking — and how can I answer that without them having to ask?”
That’s how good marketing feels genuine. You’re not just selling — you’re understanding.
Final Thought
Invisible ink may have disappeared, but human nature hasn’t changed.
We still hide our doubts, soften our messages, and hope someone will “get” what we really mean.
So the next time you read an email, watch a video, or even talk to a friend, take a moment to pause and look beyond the words. You might be surprised what you discover between the lines.
Before you go…
If you’re building an online business and want to learn how to say more with less — to write stories that connect and sell without sounding “salesy” — you’ll love my free eBook,
👉 PLR Made Simple – Your Quick Start Guide to Profiting with Private Label Rights
It’ll show you how to turn ready-made content into engaging material that speaks volumes — between the lines.
