I've suggested it too, twice, and been told both times that it's in the works.
A like button would be nice, but I think a thumbs up/thumbs down or +/- would be better. A like button only tells us how the much public approves of a response, but a +/- would also gauge disapproval. In that sense, only a like button wouldn't allow the public to quickly differentiate between neutral posts and hated posts.
It's definitely a long timing coming for either idea tho. It saves a lot of board peace when people don't have to reply with "I like your post" every time someone posts something worthy of recognition, plus it might spare a lot of flame wars if a particular poster saw they were posting things people hated without being gangpiled on by several people telling them that they're jerks.
It's also fun to be able to vote a post up or down. :-)
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