Once upon a time, there were two Yellow Pages directories (phone books). They were distributed for free, and they lived off advertising in the directory itself. And there was no difference between them. So everyone took both, and every office worker had them on their desk, using them randomly. Therefore, all surveys showed roughly equal market distribution. Companies used every white, gray, and black marketing tool, but nothing helped; the share remained roughly the same, meaning advertising sales brought in roughly the same money. This didn't suit anyone; both companies wanted to capture the entire market. Then one company found a solution: they noticed that most users had both directories on their desk, always in a stack, and office workers simply took the one on top. How to make their directory always on top? Make it slightly smaller. And thus the company very quickly captured market share. By the time competitors realized what was happening, they were left with a small share, which was also rapidly declining.