I'm a member of a couple of large computer keyboard forums. I mostly lurk on them because I can't contribute enough, due to my lack of expertise, or because it doesn't contribute enough to the conversation. I've deleted a bunch of long posts after I've realized that my comment merely summarizes the key points in the thread. That being said, I do post a "thanks for this thread"-type comment when the thread is really helpful to me, as none of those forums happen to have a "like" button. The "like" button is one of my favorite features of this forum and Reddit, although I'm not fond of Reddit's "dislike" button.