as the person who wrote the "empty bag of words", i'd like to say that i agree that a business needs to have strategy at its core. but product strategy and business strategy are two different things. get the product right first, then figure out the business strategy, then business model. and twitter isn't the only business i've invested in. i've been doing this for 27 years and have invested in hundreds of startups. i used twitter as an example but my message was based on the totality of the experience, not just one company