Talk of Kozmo has made me want to peruse failed .com companies and see if any of the models could work today.

A ton of them do exist but run by grownups. For example, I worked for a web development company which had Petco as a client. The pets.com people were trying to get purchased and they asked us to talk with them. It was obvious that they were running way too much overhead - we’d talk with their technical team on the phone & people would outright volunteer that they didn’t have much to do and were mostly waiting for the IPO lotto tickets - so they failed but today just about everyone buys pet supplies online.

The idea was fine but they didn’t understand they were in a low-margin industry. That pattern showed up a lot, especially where things like shipping were key chokepoints. Cement.com memorably failed but you can easily order building supplies in many places because the real value is proximity and there wasn’t a high-margin business as a middleman.

I always think of it as more of a DoorDash thing. There was that whole partnership with Starbucks immediately before the implosion.

You are right that DoorDash might be closer to Kosmo (and may also go under). I meant that Amazon Prime showed that a scaled up, same day delivery service could be viable and profitable

I wouldn't call Amazon Prime same day. Amazon had prime now for awhile in response to Google's Express program; these were both same-day services that delivered in 2-4 hours from order placement. Both programs were cancelled when it became clear they were unsustainable.

DoorDash and Uber were fun while they lasted.

Maybe someone will try and fail again in 10 or 15 years.