Most people know that websites show adverts. What most people do not know is that those adverts — and much of the content alongside them — are decided through auctions. Thousands of them. Every second.
But auctions online do not just sell advertising slots. They also shape which content gets promoted, repeated and pushed into feeds. The same competitive logic runs through both.
Every time your child opens a feed, someone — or something — has already bid for that space.
Start with the cooking example
Imagine your child watches a short cooking video. Just one. They enjoy it. They watch it to the end.
That completion signal — watching to the end — is valuable. The platform now knows this person responds to cooking content. And so it tries to fill every available slot thereafter with cooking.
More cooking videos. Then cooking channels. Then kitchen gadget reviews. Then recipe apps. Then a sponsored post from a meal kit brand. Then an advert for a frying pan.
How one video becomes a whole world
Child watches a cooking video to the end
Platform flags this person as a cooking audience
More cooking content fills the feed
Brands bid to show cooking related ads to this person
Sponsored posts, gadget promotions, meal kits appear
The platform did not do this to be helpful. It did it because a focused audience — someone interested in cooking — is more valuable to advertisers than a scattered one. Filling the feed with cooking content increases the chance of a relevant ad being clicked.
The content is not just entertainment. It is also bait — grouping people into audiences that can be sold to.
How the auction actually works
Think of every advertising slot on the internet as an empty space with a For Sale sign. When your child loads a page or opens a feed, that space goes up for auction. The auction lasts a fraction of a second.
Two groups of companies are involved.
The sellers
Publishers & Platforms
These are the websites, apps and platforms where your child spends time. YouTube, TikTok, news sites, games, apps. They have advertising space to sell.
Sometimes called the supply side — they supply the space.
The buyers
Advertisers & Brands
These are the companies that want to reach your child — toy brands, food companies, clothing retailers, gaming companies, subscription services. They have budgets to spend on visibility.
Sometimes called the demand side — they demand the audience.
What happens in the middle
Between the sellers and the buyers sits a marketplace — a technology layer that runs the auction automatically. Buyers submit bids in advance: "I will pay up to X to show my ad to a child aged 9–12 who watches cooking content." When the space becomes available, the highest relevant bid wins. The ad appears. The child sees it.
This entire process — from the page loading to the ad appearing — takes less time than a blink.
Content and adverts follow the same logic
This is the part most parents do not realise.
Auctions do not just decide which advert appears. The same competitive logic shapes which content gets promoted within feeds. Creators, brands and media companies also compete for visibility — paying platforms to boost their content, or earning algorithmic favour by producing content that drives engagement.
pays to promote a recipe video that looks like regular content but is a product placement.
pays to boost its trailer so it appears in the feeds of children who have watched gaming clips.
bids to place an ad after back to school search queries.
follows your cooking interested child across multiple apps, repeating its message wherever they go.
To a child, all of this looks like content. The auction is invisible.
What parents can say at home
You do not need to explain programmatic advertising to a ten year old. But you can build instinct.
Who do you think paid for this to appear?
Does this feel like content or like an advert?
Why do you think this brand keeps appearing after you watched that video?
Do you think the app is showing you this because it thinks you will buy something?
Did you choose to see this, or did something choose it for you?
Parent takeaway
Every screen your child looks at is a marketplace. Attention is the product being sold — and the auction for it happens before they even notice the ad.
Understanding this does not make the internet the enemy. It makes your child a more conscious participant in it.