Earlier quoted context omitted.
While domains are unique, how does it help Prada, Tiffany's, etc? It makes no difference whether the copy-cats are selling rip-offs marked "tiffanys.com" out of a cart. There is also more to trademark that just protecting marks. Trademark protects many aspects of the brand (see: trade dress, dilution, tarnishment, etc). Companies spend a lot of money advertising because brands are valuable, and trademark basically pr…
Yeah, I understand the value of a brand. I was thinking that, without trademark, there could still be ways to ascertain the authenticity of a product. For example, tiffanys.com could list their physical stores on their website. A fake store wouldn't fool the neighborhood for long enough to be worth the effort.
Also, there is a whole world of non point of sale branding. When you give a gift, you pony up for a real Kate Spade bag instead of a perfect knock-off (which are probably made in the same Chinese factory!) You might get those awful D&G glasses with the obvious branding instead of a perfect replica. A lot of the value of branding is rooted in the fact that humans are basically monkeys and we buy products to show the brands off in our social circles. A lot of people would knowingly buy knock-off D&G glasses if they could get the same effect for less money.
Now, I'm not arguing that this would be a bad thing. It'd save parents a lot of money if their kids could show off their "Nike Swoosh" shoes without paying a huge markup for something made in a Chinese sweatshop. But the fact that we can't do that is certainly quite valuable to Nike (and D&G, and Ralph Lauren, etc), and the inability to protect their brands in that way would certainly reduce their incentive to invest so heavily in them through advertising.