Instant messaging and live chat etiquette tips

Messages should be short and to the point.

Many Instant Messaging services limit the amount of text that can be sent in a single message and thankfully so :). There's nothing worse that receiving a 500 word IM message where the writer could have consolidated it into couple of dozen words. Again, bear in mind that you don't know what's happening on the other end, nor the other person's reading abilities or attention span. Keep your messages brief and relevant.
Don't "SHOUT"

TYPING YOUR MESSAGES IN UPPERCASE is extremely rude - it's considered shouting and very aggressive. If you're a slow typist, stick with all lowercase.
Give people time to respond

"Machine gun" messaging is a really good way to get people to totally ignore you in future. Multiple questions sent to a recipient before they've had a chance to answer can seem more like an interrogation rather than a conversation. Pose a question, then give the other person the opportunity to respond - they may not be as fast a typist as you or may have been distracted. Most IM and live chat applications these days will show in the status bar if the other person is typing out a response. As a courtesy, you should also only ask a single question in each message and acknowledge the person's answer when they do respond.
Remain polite and non-judgemental

While you may spend the majority of your life on a keyboard, I'm told there's many people who don't :). Not only may these people be slow to respond, but their responses may seem too brief, curt or bordering on what appears to be illiteracy! Try not to judge the person based on your initial conversations. If a person seems to be abrupt, there's no need to match the abruptness; remain professional but polite. Just because someone else may not use the terms "please" and "thank you", it's no reason for you not to.
Pay attention

If a person has taken the time to request a live chat with you; give them your attention. You know what it's like at a store when the person is serving you and also speaking on the phone; it's just plain rude.

Wherever possible, give the person you are communicating with your undivided attention. It's not just a sign of respect, but if you have multiple conversations happening or are allowing other issues to distract you, you may miss an important point in the other person's messages or lose the gist of the conversation.
Jargon, slang and abbreviations

Jargon, abbreviations and slang used in live chat and instant messaging conversations can help reduce keystrokes, but may come across as being unprofessional to the person you are communicating with. Worse still, if the other person isn't familiar with the lingo, it may totally confuse. Until you get to know the person better, or you see them using the same lingo, best to steer clear of it.
Humor - be cautious

Just as with email communications, be very careful about the use of humor in live chat and instant messaging communications. In fact, in initial business conversations steer clear of jokes etc. unless the other party initiates them, and even then be careful as to how far you push it. There are all sorts of cultural and personal differences among the population, so what may seem funny to you may be considered weak or even offensive to others.
Use emoticons

Most IM and Live Chat programs include emoticon features. Emoticons are a good way to clarify the feeling attached to a message. If you are going to joke with the other party, a smiley :) is a good way to clarify that's exactly what it is.
Don't use custom fonts, text sizes and colors

You might think that your message texts look groovy in 22pt. hot pink, but think of the other person. I've had some conversations where the other person has decided to be "creative" and I've very nearly had to wear sunglasses :). Just stick with standard type/size/color messaging fonts.
Probing questions

It's quite amazing what types of information people will ask over IM - including very personal questions or questions relating to business that would be considered very confidential. Don't ask such probing questions unless you know the party very well or it's directly related to the service/product you are offering - start digging too deep with a new contact about their business or personal life and you may scare them off.
Be careful with confidential information

Instant messaging and live chat applications are not very secure by default. If you need to relay or receive confidential information, some applications will allow you to run secure IM sessions - check the application help file for that feature.

In regards to live chat software, it's always best to run it via an SSL (https://) connection. While this may slow down sending and receiving as the data will need be encrypted and decrypted, it will demonstrate to your clients that you take security seriously.
Using canned text

Many live chat software applications have features that allow for storing texts that are used often; such as a response to a commonly asked question - this is called "canned" text. You select the title of the text you want, click a button and it then appears in your message window ready to send.

Canned text is a great time saving feature, but one that is routinely abused. Canned text is fine if it applies 100% to the question that the person has asked, but in most instances it should be edited to suit the situation - use canned text with care.
Think before hitting the enter key

I've been in a number of IM conversations where things become a little heated, but I always try to stop and think before hitting the enter key.

With email, you may have a few minutes before your response is sent, but with IM and Live Chat, hit that button and it's out there. So much damage is done through people not taking a few more seconds to consider the effect what they have written may have on a situation.

If you're in a conversation that's getting a little too fiery, either break it off to reconvene a little later, or finish it face-to-face or via the phone. As with email, Instant Messaging conversations lack the advantages of physical signals such as body language and vocal intonation. In situations where emotions are running high, one wrong word can turn a difficult situation into explosive.
Unexpected events

Before sending a file, image or "pushing" the person you're messaging to a particular web page; warn them/ask their permission first. With so much nasty stuff happening on the web these days, people are understandably apprehensive when something occurs during a conversation that isn't expected.
Ending a conversation

It's important to properly end an IM conversation - you may think the chat is over, but the other person may not. While you're off doing other things, they may be sitting there staring at the screen waiting for further communication from you :).

At the end of the conversation, summarize the discussion and points to be actioned, ask the other person if they have any more questions and if not, thank them for their time.
Use availability status features wisely

All Instant Messaging applications allow you to set your status; e.g. "available", "away" etc. and you can also customize status messages - use these features (wisely). If you're set to "available" but you are in fact away from the computer you can really tick people off while they sit and wait for a response that will never come :).

With live chat software, there's usually 2 status settings - "online" or "offline". When in offline status, the live chat button on your site will usually invited the person to leave a message. As with instant messaging, be sure to set your software correctly, bearing in mind that the more often you are available for live chat, the better conversions you'll experience - it really is a great way to improve your online sales.
Monitoring live chat conversations

If you run an online business where multiple staff members are engaging in live conversations with clients, take the time to review conversations for quality control purposes. These people are representing your company and you need to ensure that they are relaying the type of image regarding your operations that you want. Most live chat software applications allow for the storage and retrieval of transcripts; some will even send the transcript to the software administrator automatically via email.

Finally, as with email, bear in mind that messaging sessions can be stored, then copied and pasted elsewhere. I've seen many IM/live chat conversations being posted up around the web on forums etc. much to the embarassment of the company or persons being targeted. The term "confidential" is somewhat rubbery these days, so again, think before you hit that enter key :).