According to Christensen, "disruptive innovations" are those that create new markets through the introduction of new products or services that appeal to a new set of customers. "Disruptive innovations" contrast with "incremental innovations." Incremental innovations include efficiency or qualitative improvements upon existing products or services that are offered to existing customers. Describe what is the "innovator's dilemma", and whether you agree with the authors' contention that "architectural innovations" are disruptive in nature (or why not).