Just before you start building your shiny new product (which will undoubtedly re-define the way we think of <insert-your-market-here>), make sure you have answers to the following questions:
1. Who will be buying and who will be using your product?
2. What need does your product address for those identified in the first question?
3. How is your product significantly better than other solutions that satisfy the need listed in the second question?
Pretty basic Marketing 101 stuff, right? As bizzare as it may seem, many of the entrepreneurs and heads of marketing I meet either fail to ask these questions or fail to internally agree on what the answers are.
Before devising financial models, estimating conversion rates, building go-to-market plans, creating cutting-edge websites and investing in marketing automation, make sure you have your bases covered - truly understand your target personas, figure out if they would care about your product and why they would prefer it over alternatives.
Note that the answers will most likely change along the way, so keep asking...
PS: While in the process of posting I received Seth Godin's latest post that talks about people's reluctance to ask hard questions... great minds ;)