Online facilitation does have some unique differences that require both different applications of "offline" facilitation techniques along with some additional unique approaches. Here are some things to consider:

For many participants, online interaction is a new experience. This creates the need for facilitators to often act as guides as well as facilitators. Knowledge of technology and familiarity with an online set up are imperative.

Different Environment

The online environment presents some different experiences which include:

• No Physical Cues:
  For the most part we lack the physical communications cues we depend on heavily in face-to-face communication, for both conscious and unconscious responses. This includes nodding, seeing a listener's facial or body expression change and other body language which provides a range of feedback to the speaker as to how she/he is being understood. This limitation requires more explicit writing/reading to ensure communication is complete (listener/sender clear on intent). In addition, we lack voice tone. Think about the different interpretation if someone says the following line in dead serious tone, or mockingly. "My sister is a real pro." This is especially an issue when people used to sarcastic forms of communication go online. Sarcasm is hard to successfully carry off without tone.
• Asynchronous:
  Much of online interactions are asynchronous. The delay between interactions can create differences in response. This can be positive (people think/consider more before responding) or let emotions build up (why didn't they respond??) Those who go online more frequently may appear to "hog" the space than those who log on less, or are more inclined to read rather than post. People in widely different time zones can experience significant time lag issues. Additionally, partipants in online interaction space talk about a different sense of time or flow online which varies with group dynamics and tool (ie. synchronous or asynchronous)
• Anonymous/Disembodied:
  Many online interactions are explicitly or implicitly anonymous. Business settings almost always rely on "real names" but sometimes we feel anonymous if we can't see each other. Eue to lack of physical cues and proximity, (being invisible) we may participate with less inhibitions and norms which we would otherwise apply in offline interactions. It is not unusual to have someone behave outside their normal social "norms" online because of dismbodiment. In non-anonymous situations, there is another interesting overlay of how status or rank is or isn't revealed and how that affects the interaction dynamics. This is particularly an issue in work situations when management does or does not participate, and HOW they participate.
• Text Based:
  At this juncture, most of the online interactions are text based which puts less agile writers and those with a strong visual thinking propensity at a disadvantage. Graphics, sound and other multimedia will become a stronger part of online interaction as bandwidth increases and tools improve (applying graphic facilitation techniques and incorporation of multimedia components), but right now this is a significant bit of inequality. Putting people at ease with their writing can be a key facilitation skill. The flip side is the more you participate in online groups, the easier writing becomes!

  One more thing: text based often means having a permanent record. There is a different type of accountability. It is easy to reread to gain further understanding, or rake up old grudges going word for word with ancient posts. It can be used many ways. And it affects each of us -- know these words persist -- in different ways!