As i think black hat SEO is never useful for those website which need to be continue for long time. If you want to optimize your website for a small time then you can use black hat SEO.

Definitely NO. It can penalized your website or worse it will be tagged as a spam.

I dont like these spamming tricks to promote the page
may be its getting benefit but i personally dont like it

According to my information blackhat SEO technique not useful it is totally wastage of time.

No never effective for the website, now Google is so smart and detect black hat techniques or webmaster report your website and Google banned your website and you cant afford it

It's too risky and should be avoided
 

It's too risky and should be avoided. Whitehat works. It may take longer, but not as long as it takes to come back from getting banned.

No, it is not useful.

I dont ever like to use these spamming trics
its worst to use near to me

Hi,

Thank you guys for such information.It proofs very helpful to me.;)

It's very useful to me,as per your suggestion I'll avoid it.

For short-term planning, but it may be beneficial in the long term it should be avoided. I use an excess of black hat techniques can harm your site very much, i think. I have sen some sites have simply disappear from search engines, and they never came back!

Google Caffeine and that too made in this fashion look absolutely stunning. If you are looking for the best of these then they are the ones who will ensure that you get the very best.

useful but you'd better not use.

Yes of course usefull, use it as much as you can. It is highway to... the beginning :D

Sometimes, blick hat can bring much traffic in short time. But if your site were published by google. It would never grow up again.