Many times people are either busy at work or doing their own businesses and may have no time to chat online. Taking this into account you should not contact someone online merely for chatting when you know that this person is likely to be busy lest that person be interrupted or embarrassed not to reply. As part of good manners ask the other party if he is free to chat. If the other party is ready will enter directly into a conversation with you. There are people whose time is extremely valuable. Yet others do not care.