Ok, so this kid Watsky started a bit of a trend on youtube...fast rapping. Its almost beyond comprehensible.
Of course other people wanted to show him up considering the attention he got(An appearance on Ellen Degenerss' talk show OMG!!!!1111

)
One of the better ones I've seen was by Mac Lethal(who I heard about 100,000 years and never thought about since...)
This guy is hella fast..
Talented? Absolutely.
Marketable? I dunno.