It is now a dot-com boom endnote
But something one of the digg founders wrote on this site also comes to mind: http://news.ycombinator.com/item?id=143269
I would venture to say though that the classic rules can be broken for other considerations because the Internet is a new medium.
I will get to other considerations in a minute but the main thing to understand is that the Internet breaks the old rules by lowering distribution costs.
It makes sense to delay monetization if you have a compelling user proposition that can be scaled quickly through word of mouth(ebay,youtube,flickr) or by partnering with an 18 wheeler (google,paypal,skype).
The assumption here is that if you build a large user base it takes a very small number of paying users to make money.
Its easy to see that in each case there is a real value proposition. In fact none of these applications would exist except on the Internet.
Although some rules have changed, the old rules still apply i.e. building something with a real value proposition and then distributing it without breaking the bank.
Those that failed did not create real value in the marketplace not because of monetization.
where many people stumble is thinking in one dimension terms, like assuming Adsense is a business model (see recent posts by Josh Koppelman and Jeremy Lui) on just how big you need to be for this to be truly viable.
What I liked in the original article is that it offered a few, less obvious options for monetization.
Consider the following possibilities: your user base turns out to be very broad-based and large, your user base turns out to be smaller, but a significant percentage of them is from a particular demographic or vertical, or your product turns out to be most interesting to other businesses or other websites that want to integrate what you built into their own businesses. Each of these scenarios implies a different approach to monetization.
Given the way your understanding of a market can change as you actually meet the real people who use your site, a change in targeted user base can happen to a lot of different businesses. And if you spend too much time up front working on revenue, you may end up throwing all that work away when you confront the actual opportunities that present themselves.
For some businesses, you may have a precise understanding of who your customers are going to be in advance, and then that turns out to be exactly who they are. If that works out for you, cool. But my guess is that that's not the most common scenario, especially for a website.
It is likely common in failed web startups, also.
Google became successful because they increased per-user revenue, not because they increased the number of users.
Google didn't have their business model figured out when they started, and they seem to have done ok.