A "janizary" is a "follower or supporter". In Multichannel Forensics (book, study), it is good to flag these people as special or unique, analyzing them as an independent audience.
In some projects, the analyst classifies the twelve month buyer file on the basis of loyalty, seeking to understand how customers migrate between loyal status, and marginal status.
It is important to study how your best customers behave. Best customers do odd things. At Nordstrom, we could have offered our best customers a dozen cage-free hard boiled eggs for free if the customer made a donation to charity --- our best customers would have taken us up on that offer.
A best customer might not respond to a free shipping offer. A best customer might respond to $2.95 next day shipping.
A best customer might not respond to a BOGO. A best customer might respond to an invitation to a private party.
You'll find that the janizary will be retained at an eighty or ninety percent rate --- good because you keep most of them, bad because over a four or five year period of time you lose half of them.
The multichannel forensics framework helps you understand behaviors early in the customer development process, behaviors that lead to a customer becoming a "janizary". You want to understand if you are making decisions today that hurt the long-term growth of your business.