BDSM Click
http://www.bdsmclick.com
has banner spots and paid gallery listings for sale (see pricing):
http://www.bdsmclicks.com/list.html
BDSM for ALL
http://www.bdsmforall.com/free/
#1 Sextracker ranked BDSM traffic
BDSM for All is ranked #1 by Sextracker, you can check the stats here:
http://ranks.sextracker.com/spn.html?cat=BDSM&cls=ranks