People practise BDSM because they are aroused by taking a dominant or submissive role in the bedroom or in a relationship, because they are aroused by being disciplined or disciplining another person, having control over someone else or the idea of giving up all control entirely to someone who loves or will look after them. They enjoy BDSM in the bedroom because they are aroused by the contrast between pain and pleasure and the edge where pain becomes pleasure or vice versa, and at the idea of controlling or giving up control to another enough to explore these boundaries. As long as they are both consenting adults, fully aware of their choices and boundaries, I don't see the problem. Personal lives are private, not for society's prying eyes to judge. It brings to mind a couple of quotes... Honoré de Balzac - La Comédie humaine (1845) "For pain is perhaps but a violent pleasure? Who could determine the point where pleasure becomes pain, where pain is still a pleasure?" and Marquis de Sade: "Sex without pain is like food without taste." I myself do not enjoy BDSM in the bedroom unless I am the dominant partner. I have problems giving up control and trusting others enough - I can't be submissive. I think for people that can finally give up control, who realise that they trust the person they are with enough to do that, it can be a psychologically freeing experience. I can't speak for everybody in the BDSM community, but that is one of the points I have heard from submissives.

It's definitely a psychological thing, for me anyway, especially being submissive (well sub to my Master, and Domme to other girls). Someone's need of it can go far back into their childhood and manifest itself through the RP of bdsm. There's a fine line and everything, for some people it can do serious damage but for some it can provide so much freedom and resolve of past problems. They key is finding the right person to engage in it with you and have 110% trust, communication, and honesty.

Because they didn't get it perfect yet.

Because they didn't get it perfect yet.

My first wife and I practiced it because she did not know what to do in bed and it kept it interesting for both of us. She had been trained by a guy when she was in her teens and she liked it. So, when I met her, she introduced it to me. We talked and set up some rules for her to follow and went from there. It was never constant, unless we both agreed. She like it because it gave her some security and I liked it because I was in control.

In addition to the previous answers...because its just plain FUN!;-)

I had never heard of it until I met a wonderful lady. In the beginning the idea of tying someone up and inflicting painful stimuli was strange to me and went against my ethical principles. However, her obvious explosive pleasure in this soon changed my mind. Now it is a wonderful erotic turn-on for us both. BTW the wonderful lady is now my wife ;-)