Advertising is a weak force. Habits aren’t.

Andrew Tindall at System1 describes advertising as a weak force. It’s an idea that goes back to Andrew Ehrenberg, and I agree with it.

I don’t doubt that seeing a brand again and again builds mental availability, and that it pays off when someone is standing in the aisle. But it’s a slow, expensive way to move a person. It nudges. It rarely decides.

There’s a stronger force in marketing, and most brands spend their budgets fighting it instead of using it.

Marketing is two jobs

Strip it back and marketing does one of two things. It creates new habits, or it breaks existing ones.

Almost all the money goes on breaking. Billions of pounds a year spent persuading people who already buy a competitor’s washing powder to switch to yours. Sometimes it works. Mostly it’s hard, because people are creatures of habit, and a habit is just a decision someone has stopped making.

If you’ve read James Clear’s Atomic Habits, you know the principle: it is much easier to build a new habit than to break an old one.

So the most valuable moment for any brand is the moment before a habit exists.

When does that moment happen?

For most categories, once in a lifetime. The day someone moves out of the family home.

Until then, somebody else does the shopping. The tea, the cereal, the shower gel, the bread, the washing-up liquid were all chosen by a parent, years ago, and never revisited. Then one day the young person is standing in a new kitchen in a new city with their own money, and every one of those decisions is theirs.

They are a brand-new shopper in dozens of categories at once.

In the UK this happens on a scale nobody else can match. Every September, half a million students leave home and move into halls. It is the biggest movement of first-time shoppers in the country, and it happens in the same few weeks every year. That is the moment the Dig In Welcome Bag is built for.

What it looks like in practice

Take a tea brand. It puts twenty tea bags into half a million Welcome Bags. That’s the student’s first twenty cups in their new home, from a brand they didn’t choose but now use every morning.

In the same bag is an offer for the next box. Twenty cups, then a box of fifty, and the habit has formed before a competitor has had a look-in. The next time that student is in the supermarket, they don’t compare. They pick up the one they already drink.

That isn’t a weak force. That’s the habit doing the work the advertising was trying to do.

Does it actually work?

We measure it. Since 2018 we’ve run 196 surveys for 161 brands, asking students what they thought of what they tried. In 2025 the median brand had 85% of students say they were likely to buy it again. In 2026 it was 88%. The full norms are in the Dig In Trial Benchmark.

No ad campaign gets a stranger to that point in a week. A product in the hand, at the moment the habit is being formed, does.

And it doesn’t stop at the student

There’s a bonus most brands miss. Students go home. At Christmas, at Easter, in the summer. And when they like something, they ask for it to go on the household shop.

The teenager has always been a quiet influencer in the family trolley. Reach them first, and you often reach the household behind them too.

The better way

You can keep spending to break habits that already belong to your competitors. Or you can be there when the habit is made.

One of those is a weak force. The other is human nature.

Every September, half a million people start choosing for themselves. The question is whether your brand is the first thing they choose.

Get your brand into the bag. Talk to us.