That does not necessarily happen on the web. Everyone knows about Amazon and has bought from them. Everyone admires Amazon and Jim Bezos. While they have yet to turn a profit, everyone assumes, I believe correctly, that they will eventually succeed. Books and music can be sold successfully on the web.
Travel reservations work.
Computers and software work. That does not necessarily hold true for most consumer goods. As already pointed out, supermarket products cannot be sold profitably. Goods sold by catalog companies can be sold on the web. But we are finding out something interesting in this field.