I never used 'like' button in the sense of upvote or 'like' in Facebook. I always used it for 'bookmarking' purposes. Though Twitter added bookmarking feature,

I never used 'like' button in the sense of upvote or 'like' in Facebook. I always used it for 'bookmarking' purposes. Though Twitter added bookmarking feature, it is somehow useless for me as I can't undo this bookmarking operation for individual tweet but I can simply unlike a tweet. Personally I think Twitter is just not suitable for debating. I mean you can't articulate your view in 280 charscters. Facebook is better suited for this.