Depending which generation you ask, the emoticon (or smiley) is either the harbinger of the apocalypse of the English language… or an indispensable tool for getting your message across in the right way quickly and easily.
If something needs a reply right there and then, but you don’t have time for a full-blown ‘Dear’ or ‘Yours Sincerely’, you want your response to be received without seeming blunt or brash. But in the tone-free world of emails and texts, a one-word reply might be taken the wrong way unless you have a super-quick way of letting them know how you feel. That’s where this little fella comes in : ) And his winky mate is pretty handy too when you want to let someone know you’re joking ; )
It’s also important to know the right context to use them in and to be consistent, of course. If you sign off your angry tirades with a smiley face not only will people not know how to take it, they may also confuse your genuine smiley messages with angry ones.
The sad face : ( is probably best avoided as it is usually understood to mean you are feeling sorry for yourself and just want a bit of sympathy. If you are actually upset the sad face will probably make it seem less serious than it really is.
Of course, these friendly faces are suited to your less-formal business relationships, or your already well-established ones. They can be absolutely invaluable in ensuring your email comes across with the intended tone, and will save you time versus the traditional salutations. Try it, your contacts might like it : )