As stated, this is for extreme overclockers. There are actually professional overclockers and it is very competitive. Those guys are always looking for an edge.
Typically they have to rig something special up, because standard mounting materials are unsuitable for LN2. Specific mounting for extreme overclocking is just coming to market now, even though folks have been doing it for about 20 years.
If you are overclocking memory (and yeah, the pros do that) you will need something special to go over 3 Ghz. And yes, its for benchmark busting and going for world records. The cost for this is means nothing if your overclocking team wins 10 grand at a competition.