Online can never replace real life. I think many in this thread have made the point that it is 'not the same' and I do not disagree with that. What I do contest is that this means that it is not 'real' or that it is lesser (which, again, no one has actually said but there is always that feeling that that is what many are thinking...)

One thing that is not usually mentioned is that for many OL is the ONLY way they can get their BDSM. There are people who are too isolated, can't find their local scenes, can't find people close enough to them to play with in real life. These people would love to play in real life but can't due to some circumstance or another.

Another aspect of OL that I think is important is that it gives you the chance to 'try before you buy'. A lot of people have fantasies about BDSM but many of them are not aware of what it is actually like to suffer some of the things they read about in stories. They talk about wanting to be tied and whipped and have clamps on them and so on but in some cases, if you actually tied them up and whipped them, they will find that they hate it. Online may not be as intense as real life but if you get a small taste of it from an online/self inflicted standpoint sometimes it tells you if you will in fact like the real thing or not before you start trying it out for real. I think this is an important screening process which can be a great aid to dominants in the lifestyle - if someone can't follow simple instructions or withstand the small torments of online tasks, how can you be expected to do it in person?