15 years ago you could repeat «buy plastic windows» 50 times — and rank TOP. Today that's a path to penalties. How BERT/MUM really measure quality.
About fifteen years ago, SEO was primitive: write the text and stuff «buy plastic windows» in 50 times. The robot saw high keyword density and pushed you to the TOP.
Today, attempting to fool the system this way will bring harsh penalties.
Modern Google runs on machine learning. The key algorithms:
They can analyze natural language. They understand synonyms, context, and meaning. Keyword stuffing = red flag for them.
Google evaluates content quality through the lens of user behavior. How does it work?
🎯 The experiment: the algorithm puts your site at position 5 «for testing». The user lands on you, sees unreadable spammy text, instantly closes the tab and returns to search.
This is called Bounce Rate. For Google, this is a clear error signal: the site didn't solve the problem. You'll be demoted.
And vice versa: if the person came in, read the article, looked at images, went to another page on the site — the system records a positive signal. This is Dwell Time.
You need to write text not for machines, but for people. Machines have long learned to understand human language — now they evaluate whether people liked it.
🎯 The 2026 rule: quality content is your best code. One expert text of 1500 words with facts and structure will beat 10 «10 tips on choosing plastic windows» articles.
🎬 In Lesson 4: the technical part — speed, mobile-first, HTTPS. Without it, even perfect content won't reach the TOP.