I was just talking about this today. I believe common investors will want to see a working business model earlier in the product. The potential for early revenue with real customers (i.e. not ads) will be more attractive.

I think it's unfortunate. Capital intensive start-ups will be at an even bigger disadvantage.. in this case, I would agree with andreessen: raise as much as possible. I've always believed in creating value before you capture any, and that will be more difficult if you have to focus on your business model early on.