TLDR but it seems the topic has drifted. Let's try and re-direct this.
I am divided on the like system on the forum. Seems a little one sided without a dislike button. As it is, the advantages are that a quick like can save a member from needing to type an "I agree" or "+1" post that might risk cluttering up things. If a reply has 25 likes on it and the reader just googled their way to the post, they can easily tell that whatever was said in that post is respected by other members and likely to be accurate.
I frequented a different forum that had a user reputation system. Liking and disliking on posts would influence a rep bar near the avatar. This can quickly identify how much a user is respected in the community. How much +/- rep a like or dislike gave depended on how much the giver had. If someone with awesome rep gave a like, it would be an order of magnitude more rep-giving than a noob. Unfortunately respected =/= knowledgeable. While someone could rack up a "He's the man!" status on rep in one forum let's say beer brewing here, they could give advice into the sake forum. While they'd have high rep they could also be posting perhaps with no knowledge of process at all. This could yield several quick dislikes and suddenly damage the mis-informed advice giver's rep. Comes down to rating a user vs the exact post. Also a somewhat flawed system to work with.
As far as myself, I try to give things that will have people liking just so that I know I'm helping out. If I spend a half hour to detail out some process in exquisite detail, it's a little heart breaking to see what can be interpreted as being unappreciated. Other times I'll make a joke in one of the less serious threads just to make someone smile and not really care how that turns out.