EDIT: since Adredreseen Horrowitz invested, I assume it's likely not a repeat from Y2k, and I'm really interested in what they're doing differrently
In 2000 only 41% of all US households had internet access. Now it's 81%. This number also doesn't include internet in your pocket (74% of all Americans have some kind of mobile broadband).
The idea of "groceries on the internets" was never bad, it just tried to enter a market that didn't actually exist yet. They also tried to do too much, too quickly: i.e., launching into low population density markets that had zero chance of being cashflow even in the next 20 years. Notice that Fresh, Instacart, Google Shopping Express, and all these other perishable delivery companies are now strictly only in the densest urban areas where there is sufficient economy of scale to make the numbers work.
There are also some smaller contributors to success: people in general are much more willing to put their credit cards on the internet and buy things through the internet. People are able to access the internet while on the go. In the case of Amazon and Google they're leveraging a brand and existing user base that they've been building for years. The state of web tech also means the products are far less painful than before - keep in mind that 2000 was before AJAX, where every click of every button meant a completely new page load... over a connection that is likely dialup.
The game is very, very different from the way it was in 2000.
The negative Karma points were totally worth the responses. Wish there were some more with more specifics on said startup.
I'm waiting for "datahaven" to be a viable business, though. That would be really fun.
The difference is that they got their logistics and pricing down. The Y2K companies didn't.