Long-Tail Keywords research

Hello,
I have a question for long tails researchers. I research them via amazon, google, bing, yahoo suggestion. I have read a lot about this and a lot of people doing that.

Here is the question:
It is necessary at all worrying about a volume of monthly searches for keyword or you get decent traffic via other relevant keywords and LSI based keywords you are using in the text?

Thanks

johnnierush102 said:

It is necessary at all worrying about a volume of monthly searches for keyword?

Click to expand...

I don't look at that when it comes to long tails, it's not important imo.

Ok, but I want to be ranked for some keywords which have some good amount of searches. Will LSI keywords done the job, if not how?