- Red flag #1: The product is the most expensive and full featured product in its own line.
- Red flag #2: Most potential customers of the product already own several products which can do everything the fire can (e.g., their phone, their tv, their x-box), just slightly more poorly or less flexibly.
- Red Flag #3: There is already a slowly growing segment of their exact market which is already significantly cheaper and crappier (i.e., digital picture frames mutating into Android ebook readers available at home retailers).
- Red Flag #4: The author can't resist throwing in praise for the quality of the product, e.g., "There is scalable technology at its core that the present-generation iPad lacks — the extensive use of the Cloud."
- Red Flag #5: The product is being sold at cost or less.
OTOH, the Amazon Fire is cheaper and crappier than the iPad, but if that's all it takes to be a "disruptive innovation," you don't need Clayton Christensen or the Harvard Business Review to explain it to you.
I don't know if the Kindle Fire will be successful, if you think "disruptiveness" is the key here, it has to maintain a very careful balance between the slightly higher priced, higher quality iPad and its own lower end competitors.