It's easy to send good will towards others when they are nice to you and good to you. But supposedly, to realy transform yourself and progress as a human being it is best to bestow good will on those who are more difficult. For example, if somebody raped you or something.
The idea is that anytime you want bad things to happen to another person, you open yourself up for bad things to happen to you. When you do transformational sharing (sending good will to those) who have done the worst things at you, that is when miracles happen for you.
I find this difficult because it seems to me that when somebody does something bad to me, the last thing I want for them is happiness and success. I don't want them to be healthy and win the lotto. I accept others for who they are, and don't treat anybody bad. But if somebody is treating others bad or not accepting them for being different, wouldn't I rather send bad will towards them than good will? Like why would I want good things to happen to people who mistreat or disrespect those who are different?