Well, in the case I mentioned (yep, you @doggiedude ) it was the absence of any response that made me think I'd trod on toes. 'Like' is appreciation/acknowledgement you can show with a single click when you don't have anything to type back. And there are those like @LinnyV who like collecting them - it's effortless to do, so if someone's earnt the approval why grudge them a Like even when you also comment back? I view it like I would smiling or nodding during conversation. If someone talks to me and never does either of those things, I start feeling uncomfortable. You can also look at someone's 'Likes Received' statistic (or particularly the ratio of Likes-to-Posts) to get an idea of how helpful they are, or how much their opinions reflect the general consensus, which can be helpful in interpreting feedback from them. Obviously it's not a perfect index - they might be funny but not helpful, they might have made heaps of posts before the Like system was implemented, they might be unlucky in that people that approved of their posts didn't click Like, etc - so I'd generally still judge each post by its merit rather than the reputation of the poster, but it's a fallback. And if you click onto a thread and don't have time to read through a whole lot of lengthy posts, looking at the number of Likes each has collected gives an idea of which others have appreciated most. I feel so Gen Y right now. Maybe I'll start a netiquette blog.