The reason that the web lost faith in charging for stuff is that marginal cost is so low. What is the cost to 37signals of having another customer sign up for one of their services? If I sign up for the $49/mo. Basecamp product, they are offering me 10GB of storage as well as bandwidth and application processing. None of that has a high marginal cost. Maybe $5/mo? Plus, many users won't use all that space so it's a maximum of $5, but the average marginal cost would probably be a good deal lower.<p>So, while many applications might have very high fixed costs (like paying people to create wonderful applications like those in 37signals portfolio), they have marginal costs that are so insignificant that people would like to charge customers less and get more customers - often ending up with them wanting to give it away for free for maximum uptake (with the whole profit thing put off until later).<p>Beyond that, some applications you can't charge for. 37signals has a portfolio of applications that don't get better for users as more people use it. That's unlike Facebook, Delicious, Digg, Wikipedia, etc. If those services charged a monthly fee, it would degrade the content that the sites have. Facebook isn't useful if they only retain 10% of their user-base because they're charging $10/mo. So, some websites must try alternative ways of monieization since charging users isn't an option.<p>Finally, the web often forgoes charging for stuff because they get big paydays for it. StumbleUpon got $75M. Reddit commanded at least a few million. Digg is looking for hundreds of millions while having no plan for profitability. Facebook is looking for tens of billions with no plan to make money! Jaiku was bought for millions. YouTube for $1.5B. I don't need to go on. People get rewarded for the behavior of creating a site with no expectation of profits. As long as that's working, they'll keep doing it.<p>Personally, I think 37signals has the right idea. But that won't stop people from making free sites with no profit plan which they hope to get bought since it happens enough. Yeah, I'm not going to create visions for myself of taking over the world, but others thrive on that. As long as there is some potential of getting bought for millions and a low marginal cost, people will create those free sites.