I actually posed this question myself sometime back, but I later came to realise that I was just looking for ego-massaging and I now take the view that if I can post an answer that helps somebody that is its own reward. If they don't answer for any reason, and there are many - they may find the answer elsewhere and not bother coming back, they may not want to login again - well, so what? It won't stop me posting answers if I know them, and on the occasions when somebody does answer it's just a bonus. (can't say I'm bothered about the stupid star system though)