short for b
romotion. Not necessarily the normal type of SPAM
but also a more benign form of it which is used to advertise non-commercial websites. Still obnoxious to many people, especially if it's off-topic
Typical BSP statements look like:
"Also see my homepage, it's really cool!"
"BTW, I run a site that deals with pet hamsters. Come visit me!"
"This site sucks. Come visit mine instead!"