short for
blatant
self
promotion. 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!"