There is a big difference for some between wearing a "collar" and being "collared".
From the slave's perspective however:
Perhaps it is becuase some people see the relationship between a Master and slave to be much more "binding" than ever a relationship between two free individuals who consider themselves to be "equals" could ever be.
It is said that there is no greater love than the love of a slave to her owner. Bound by more than just his will. The passion of the slave for her owner is absolute. She is more than just property and can do no less than give of herself to him everything.
Many say a free woman is incabable of love as the slave loves. For she always keeps sometimg for herself.
Only the slave is completely open to her owner in all ways, there are no secrets, no hidden desires, she is naked before Him in all. She bares forth her essence to him in everything, and he deepens her servitude with his strength over her, for she is his most cherished property. In this the slave is allowed nothing but utter trust and total devotion to her owner. Even her own deepest fears must be put aside to please her owners desires.
No free woman can truely give this much of herself. It is something truely rare in the world.
"The pride of a free woman is the pride of a woman who feels herself to be the equal of a man.
The pride of the slave girl is the pride of the girl who knows that no other woman is the equal of herself.' "