What should I write about in my newsletters?

I think two of the most important words in marketing are:

What's next?

That's the feeling I want someone to have when they finish one of my emails.

Not:

"Thank Christ that's over."

Not:

"I wonder what he's trying to sell me this time."

But:

"What's next?"

Your newsletters are an opportunity to continue the relationship you started when somebody first joined your list.

So write about things that provide either:

Tangible value.

Something useful. An idea. A lesson. A different way of approaching a problem.

Or:

Emotional value.

Something interesting. Funny. Surprising. Relatable. Something that makes the reader feel understood.

Ideally, you'll often do both.

And no, I don't think every newsletter needs to justify its existence by generating an immediate sale.

You can have intentional promotions for that.

Your newsletters have another incredibly valuable job:

Keeping people paying attention.

That doesn't mean you can never promote something in a newsletter.

Of course you can.

It means I wouldn't look at every email and ask:

"How do I monetise this?"

I'd ask:

"Is this worth opening?"

"Is this worth reading?"

And most importantly:

"Will they want the next one?"

Because if the answer keeps being yes, you've built something far more valuable than a list of email addresses.