Why is this important?
Customer identification is important for the following reasons:
1. It helps you to match your product/service to a targeted audience
2. It allows you to focus your marketing efforts
3. It saves you time and the pain of dealing with tire kickers
We only have so much time available every day and we need to apply it to best effect. Having a targeted customer group saves time and makes your advertising efficient. Your messages can be written with your customer group in mind. This allows you to move from a scattered shotgun to an accurate rifle shot approach.
I market to people who want to start their own online business. I sell evergreen products that I know have high numbers of repeat sales which help me build residual income. The lists I use and my advertising efforts are all focused on this demographic. If you have hungry people they will want to eat the food you serve up. If someone is happy with a day job working for a boss then they won't be hungry for marketing that accentuates the benefits of working for yourself (e.g. How may takers would you have for selling a dinner package to people coming out of a buffet?).
Know your customer, meet their hunger and prosper!