An online video that when released attracts so much traffic that it crashes your site, the same way a blockbuster movie sells out theaters.
"Dr. Horrible should prove to be a profitable venturein the end, and will probably establish itself as the 'sitebuster' hit of the summer..." – Tubefilter
Pertaining to graffiti, when a toy hits a wall that has already been burned by an established writer, to make it look like they know each other, in an attempt to gain some credibility
If you sidebust, you just might get your ass beat.
In pro wrestling, a spinebuster is a move that involves a wrestler picking up his opponent, spinning, then finally slamming them down onto their back, or spine.