Tech Knows You a blog about online advertising

Independent · ad-funded · deliberately

The internet is reading you. Read it back.

Tech Knows You is a small blog about online advertising — the auctions, the profiles, the money. It is funded by the four ads below, and by no others: the subject matter pays the bills live, on this page, openly, and nowhere else on the site.

The four ads the algorithm just chose for you

Picked in a ~100-millisecond auction as this page loaded. We never see them — they render inside Google's own sandboxed frames. Every essay page on this site carries zero ads.

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the algorithm's got nothing here
Advertisements
an empty frame — no read on you yet
Advertisements
the auction came back empty
Advertisements
the algorithm is still thinking

$0 spent on digital ads worldwide since you opened this page · ≈ $25,367 every second · how we got this number

The writing

All essays →

Latest how-to data 5 min

Why am I seeing this ad?

Google and Meta will both show you the file: the inferred income band, the uploaded contact lists, the reasoning behind every ad. Reading it is the strange part — the profile is a mirror with opinions.

Read the essay →

The 100-millisecond auction

Anatomy of a single ad impression, from the first byte of HTML to a cleared trade — all before the page finishes painting.

The $25,000 second

How a shelf of trillion-dollar forecasts becomes the per-second counter on our homepage — the arithmetic, the caveats, and a standing promise to correct it.

The ads that follow you

One idle look at a pair of boots, and three weeks of machinery swings into motion — how retargeting works, why it won’t stop, and how it takes credit for a purchase you’d have made anyway.

In-market for a funeral

The targeting machine is wrong-but-confident by default — and when its confidence lands on grief, the person on the receiving end pays for the error.

Made for advertising

Inside the arbitrage economy of pages built to host ads rather than be read — and why this ad-funded blog owes you a straight answer about the difference.

Do ad blockers break the deal?

The content-for-attention bargain was never signed by the reader — so who broke it first, and what would honouring it even look like?

How this site makes money

Four ad tiles on one page fund everything here; these are the published commitments that keep that arrangement honest.

From the glossary

Retargeting

Showing ads to people because they already looked at something — the reason a pair of boots can follow you around the internet for three weeks.

The whole glossary — the one the ad industry hoped you wouldn't need →

Talk back

This blog reads its mail

Disagree with an essay, spot an error, or have a stranger-than-fiction targeting story of your own? Write in. The best letters get published — with your permission, never your name unless you want it.

Write to the letters desk →