I think it really depends on what kind of business your are building and what kind of market you are addressing your offer / product.
In some case, where you sell directly something and people buy, this pre-order method clear landing page can work to validate the idea.
In other case, the traction with users using your product, daily, monthly, can be also strong signal that your are providing value. (even if no one pays)
I think both of that can work. But I deeply believe that if you have people using your product frequently (daily, monthly), you will, sooner ou later, find out how to make money from them. Sometimes, we don't have to impose a business model, it's the reaction of the market which give us the direction on what business model fits with our market. (listen the market)
To sum up, personally, I think it depends.