During Market Analysis you determined which type of end users will be affected by the product.
In order to know for whom you make the product, what his / her needs and wishes are, you will be better placed in the way these end users do this.
It is a common mistake that the designer / developer thinks she/he knows exactly ow his end user thinks and acts but often they are not enough informed and in many case biased more they think they do.
By getting into the skin of different people and personas you are forced to approach the concept from different perspectives and with different habits and background. In this way you can discover the real needs and find frustrations that you have not experienced yourself.
Do some research by really talking to the potential users of your product by executing interviews with the focus group and also colleagues, friends, relatives, buddies…….
Making a mood board to visualise the needs, habits, expectations of your persona’s enhances the power of this tool.