How to make money on the web

According to the New York Times lots of media companies are investing in the web, looking for a business model.

I have a simple question – when folks wonder ‘how do we make money at this?’, why do we instinctively forget the models that have come before that already do?

Amazon.com. Yahoo!, eBay, Craigslist, Google, Salon (I believe in the black).

What is similar about their business models? Do they recognize some essential nature of the web? Any other good examples?

And when we talk about new models for news gathering versus the old, and worry about how in-depth journalism will get financed, is there something related here?