why do you choose un-real time register service?

[dnol]

I know there are some ,even famous register service ,which provide .com register service,they provide un-real time register,
some people are custom to that ,why?
reliable?
a aritists even lost her domain name before and I got her back from an American company which do domain catch and back order service. before that,the girl had enough time register ,but she chose an unreal time register service.
why?
she said she used it all the time...