I was going to post this as a reply to something but it veered off topic slightly so I'm starting a new thread.
I was spanked as a child, by my dad. Not often, and I think I was actually way more scared of my mom's hysterical scoldings than his spankings, mostly because she can be a little bit crazy when she's like that. My family history is a bit complicated I guess. From my parents I suffered more from neglect than abuse - they are nice enough people but neither of them really have any idea how to deal with children. As a teenager I got verbal and emotional abuse from my mom as she resented me for still being around when she wanted to start a new life. Social workers had to get involved and I was a bit screwed up by it. The abuse bit of my childhood really comes from my brother though - I was physically, sexually, and emotionally abused by him. To be honest, I lay more blame with my parents for not noticing anything than with him, since he was just a kid too.
In any case, this has brought up a few issues for me with spanking:
1) I have a fear of becoming an abuser. When I was little I was quite violent because it was what I knew, and although I haven't hit anybody for years, I do worry that it could reemerge. So this can make spanking difficult although to be honest, it's less to do with the physical side and more when Danielle has a hard time submitting and I have to battle against her. It kind of feels less consensual then, you know? Even thought it isn't.
2) My childhood experiences were not consistent or regular and depended a lot on people's moods. We're a tempestuous lot in my family! I'm mildly autistic and part of that is a heightened need for order, predictability, and control. This makes spanking really good for me because I can set out rules with particular consequences and know that things will be consistent in a way that makes reality more acceptable for me!
3) One thing I have become is self-disciplined. I needed structure and what I had was being ignored so... I made it for myself. Part of the DD relationship we have is, I feel, me sharing something I can do with Danielle. Our relationship is full of these kinds of sharings - Danielle will make official-type phonecalls for me (they freak me out) and I get her to read-through things I'm going to send to people when I'm angry or whatever so that she can check I'm not letting my anger get in the way of resolving the issue. What I share is an ability to organise and motivate... even if that motivation is avoiding a sore butt
4) I suffer from depression and for me one of the biggest parts of this is a feeling of powerlessness. As I was powerless to change my situation as a kid, I get run-down very easily and feel like things are kind of hopeless. The good thing with spanking is that.... I have the power. Having power to improve things makes an awful lot of difference to me.
5) I've said this one before. The alternative to (1) - I do have anger management issues. I don't exactly want to say that spanking is cathartic, because that would give off the wrong impression, I think. But having a structure in place for how to deal with Danielle makes me less inclined to get angry with her, as anger for me is usually born of frustration and fear that things are out of my control. So spanking can be a good sort of vent in that way when I would otherwise freak out and get angry.
I'll echo what the other tops here said about why they got into spanking - Danielle needs it, and I want to give her what she needs. It just so happens that it's worked out pretty good for me too.