Alright, before you read this, keep in mind that while ignoring haters is one way of dealing with them, it's not a solution in my opinion.
Okay, now, I know that our fandom is kind-of past the stage of having to fight for their internet lives, but this also applies to other aspects of life, so I am making this post. When it comes to haters, everypony knows that they aren't worth getting mad about or making a fuss, and while that is true, ignoring them won't solve anything. No matter what you say, a hater will definatly do his best to make fun of you or insult you, but, if you don't say anything, they won't stop, they will never stop unless you do something. So what I'm saying is that a hater isn't a reason to get angry, and ignoring means you don't want to deal with them, which means you are at least somewhat annoyed, which means you're somewhat angry. The best way to deal with them in my opinion is to make them question themselves, because even if they reply like an eight year-old, they will think about it, which may or may not lead to him reconsidering his ways. But at least it will do something, because ignoring won't do anything. For example, there was an episode in Southpark where Cartman was making fun of breast cancer after Wendy made a lecture about it in class, as the episode goes on, Wendy tries to make him stop by trying to explain about breast cancer and how it is serious matter, therefore he shouldn't make fun of it. But in ordinery Cartman fashion, he continues to do all he can to make sure she can't stop him. He even went as far as lying to his mother, Wendy's parents, and about everyone else in the school about him wanting to be friedns with Wendy, so no one will have the power to stop him from going about his buisness. Wendy gave up on trying to stop him, and he continues to make fun of breast cancer in a fake lecture in-front of the class. Eventually, she decides to take him head-on once and for all, and beats the living *SQUEE* out of him. And I'm not saying that we should go violent, but we can't afford to be the pin cushion of the haters. I know I haven't given too many alternatives to ignoring haters, but I figure we're all smart enough to reply sophisticatedly. In conclusion, not facing your problem doesn't solve anything, and while you shouldn't reduce to a haters level or anything, you should try to make him think about what he said or is saying.
This is purely my opinion, I'd be happy to hear your thoughts on the matter. And thank you for listening to me.