I've been bothered by this question for a while.
Every time I see a new reply answering my questions, I will automatically press the Thanks button.
I have observed that many people would add a post at the end of their thread to express their gratitude. However, I can't always read my posts on time and sometimes I would think about my questions and the consequent replied over and over again before I can decide whether I will finish it or not. This means there may be a three-day or five-day gap. There seems to be a dilima. If I post, simply to express my gratitude, it will waste teachers' time which can certainly be better spent. However, I will feel that I am being rude if I omit so.
What do you think of this mattar?