I agree with most posts, but .BIZ is not a failure.
You just need to know how to approach its end users.
Lets face it, its not a domainers market for .biz
However, it is still a gTLD (and +50 cents as of October the 14th)...
If a small to medium business wants a keyword that describes what they do, and the .com is gone (for whatever reason, from being used, to being wayyyyy to expensibe), .biz is a viable alternative.
Is it ideal?
No.
Does it do the job and get it done in SEOs, while still being a GLOBAL TLD?
Yes.
None of the above have failed.
in fact, many ccTLDs that were marketed as other than their original country code purposes (.ws, .cc...etc...etc...) are the ones that might be looking at being granted a 'failure' certificate.