Here we have the special word "Metafrage". A Metaquestion is a question that can be answered by Yes/No, provides no information what the other wants or needs, and any yes or no answer wont tell him anything. Its often just a polite noise, that becomes impolite, if used to often, e.g. in terms of moms just calling "Can you help me?" hurrying away without telling what kind of help she needs, assuming or better say commanding a "yes" as answer.
Its like joining an IRC channel with: "Can someone help me?" Most often nobody would answer, same to "Is someone here?". So a salesdroid starting conversation with a "Can I help you?" is a helpless newbie compared to someone who joined IRC first time by webchat.