I can feel he is a nice guy and even one day he was busy he still sent me an email telling me he would write me back officially later since he was busy packing for his trip. I am a Chinese girl and he stayed in China for three years. I don’t think it’s a big deal and based on my previous experience people usually meet only after 2 or 3 emails. This isn’t exactly a great example for why winking and rating are worthwhile ways to express interest. I will admit, though, that these methods are often used by people who know that the likelihood of a response from someone is slim.