Customer Archetypes are built from understanding your customer's pains (the problem[s] they need solved), their ideal gain (the solution they want to have that solves their pain) and the job they want your product or service to preform.

How do they buy? Where do they buy? Where do they shop? What matters to them? What influences them? How do you reach these influencers? Is the user different than the payer? Is you're buyer within an organization with certain policies in place? Create context around this persona to better understand them and how you need to approach the situation.

Coupled with demographics (age, sex, geographic location, habits, characteristics, education, ethnicity, values) you should be able to literally compose a list of who your ideal customer is and this will help establish who your customer segment is comprised of.