^No, the original phrasing of the question is correct.

Whether this website is useful or not depends on if and how you use it. It can certainly help.

See it as a tool, like a hammer, which is totally useless if you need to paint your wall, but very usefull to drive a nail into wood. It all depends how you use it.

It depends on you, for example i learned from my mistakes, ones in a week i'm trying to write here some an interesting topic and teachers corrected me, after correction i learned from my mistakes and another time i'm not gonna write in a wrong way.  ;)

The part of the website that enables me to locate professional teachers and pay for lessons has been very useful. The (two) teachers I use couldn't be better, skilled at teaching and completely professional, and lessons over Skype with video--and teachers who know how to use screen sharing and Google Docs--are very effective.

The part that lets me find language partners has been very useful, but as many have noted it's not easy to find a good language partner. 

The other features--this forum, the "notebook entries," the Q&A--are, shrug, well they're certainly useful and they don't cost anything, but they aren't a way to learn a language in themselves.

To me, italki is <em>mostly</em> a marketplace for connecting with paid teachers--and I've found it to be excellent for that purpose. 

I like this website quite a lot. I think as any other websites, you will find people with different interests, although this is supposed to be a language learning community, but by and large I only have good experiences, people have been very helpful and correct. 

If there is someone expecting to learn a language only by being here, he/she is wrong but as another tool it might help you to brush the language you are learning up.