YouTube.com's $8-million cash injection earlier this week from Sequoia Capital has put the spotlight yet again on cool Web 2.0 companies with uncertain or no business models. As much as YouTube is extremely popular (more than 100 million page views a day), it really hasn't got a business model yet - other than plans to cautiously introduce relevant-based advertising. The key question facing YouTube and other popular Web 2.0 services is whether they can cross the chasm from free to fee. In other words, can they convince enough of their free-loading customers to actually purchase premium services and/or accept advertising. In any event, I've using YouTube's financing as the basis for my column in today's National Post looking at the free-to-fee challenge and why far too many Web 2.0 start-ups will fail to cross the chasm.