* if you need your commands to be defined somewhere else than in the

``Command`` folder;

* if you need to register the command conditionally (depending on the

environment or presence of some dependencies);

* ou want to reuse the command with a different service or different

configuration, without having to extend the command - you could just

define a second service with the same class;

* if you need to access services or configuration parameters in the

``configure`` method.