"awak semua", the word SEMUA means more than one, means All of you. "kamu", "awak" and "kalian", all can be singular or plural. Similar to English YOU. So you need to understand the context of the whole sentence (just like in English when using YOU). You can choose to use any of those 3. All are correct. 2 or more is considered plural in Malay. Anda Lol, it has nothing to do with commercials. Anda is a polite and formal way of second-person pronouns. The proper way to use ANDA is when you can't see and you have no idea who is/are the second person(one way communication) like in the notice board, public announcement even when you write or chatting online (formal). When you use ANDA it eliminate the social status, age or rank. In commercial mostly the one on TV, it is a one way communication as you can't respond back to the commercial as it talks to you. So the most appropriate second-person pronoun to use is ANDA. While when you talk to a friend or in formal face to face conversation, try to avoid using ANDA.