I don't understand how there is "so much space available helping companies managine their incoming data". There's Resumator, JobVite, JobScore, Taleo, Brassring

I don't understand how there is "so much space available helping companies managine their incoming data". There's Resumator, JobVite, JobScore, Taleo, Brassring, OpenCATS, Healthcaresource, MaxHire, Vurv, (I can list 60 more if anyone would like.) The point is, what need is this filling that isn't already filled? I wholly welcome better technologies to help employers - but I need to know what makes the technology better and their tour page doesn't ring any "innovative" bells for me.