I admit it: I'm a massive wuss when it comes to dentistry.

I hate the glossy chair, I hate the weird light fixture, and I hate the horrible suction machine that gets stuck to your tongue.

These days, I tend to just tell the dentist on arrival that I'm a slightly nervous patient. Usually, this seems to work better. Except, that is, for one time when it really didn't.

The dentist looked into my mouth, made some tutting noises, and then told me: "I'm not going to use anaesthetic. You don't need it."

"I'm not going to use anaesthetic. You don't need it."

This, dear reader, scared the absolute shit out of me. "What?" I sputtered at her. "Why would I need anaesthetic? What are you going to do?". She looked at me like I was an idiot. "You don't need it", she said.

Eventually, I worked out what was going on. She was about to clean between my teeth - a procedure so routine that it needn't worry anyone, and sufficiently painless to be well below the threshold for the administering of painkilling injectables. But by announcing it so literally ("I'm not going to use anaesthetic. You don't need it") and without any of the proper context, her words instilled the complete opposite of their intended effect.

Mark my words

This event pops into my mind whenever I see an exclamation mark in a piece of marketing copy. Usually, the exclamation mark has been placed there because the writer wants to communicate that the thing being sold is exciting. But the problem is that no one has ever been made excited by punctuation alone.

And so what function is it fulfilling? At best, none at all. At worst, it's suggesting a sort of pleading desire that you, the reader, should just find the thing exciting. You're not being given a reason so much as a desperate instruction. It's a bit like calling something 'humorous'. Given that that's exactly the sort of word that a powerfully unfunny person might use, the description only dampens expectations.

In other words: communication isn't about telling someone that something is exciting or funny or upsetting or interesting. It's about convincing them. Or better yet, making them feel it right here and now.

Why bother with an exclamation mark when you could just tell me something exciting instead?

Bank on it

So, copywriters and ad creatives know that if you're trying to advertise a bank, for instance, you don't do it by saying "your money definitely won't go missing in our bank". Historically, you do it by showing grand old architecture and playing baroque music - cues that suggest a financial institution is safe, reliable, sensible. You don't need to even mention the fear of losing money or the ways that you can protect against it - sometimes a vibe is more important than a reason.

And while most of us won't be advertising banks, writers and editors are frequently engaged in the process of trying to tell a reader how to feel, or how they're likely to feel. It could be a product review ("you're going to love this office chair"), an interview with a famous person ("this ageing rockstar says some upsetting stuff"), or a piece of marketing copy ("the new novel about robots is exciting and you should preorder it"). In every instance, communicating this idea to the reader effectively involves more than a blunt insistence that it is so.

In marketing, some of these ideas are bundled together in 'signaling theory'. At its root, signaling theory is about addressing the information gap that exists between seller and consumer (I know that my cranberry juice is tastiest and the sweetest on the market, but you've never tried it). The choices I make around pricing, packaging, ingredients, stockists, advertising style, and container type will all send signals to you as the consumer. If I do my job well, these will all communicate the idea that James's Cranberry Delight is astonishingly good.

If I choose the wrong signals, send them inconsistently, or send signals that are incompatible with one another, the communication falls apart.

And James’s Cranberry Delight becomes just another reason for my accountant to loudly sigh at me.