Need some advice with long tail keywords.

Hi guys,

I am currently building a new web site and the main keyword according to G tool has quite some nice traffic and the competition is okay.

My main concern is that whenever you talk about long tails you always say that find the ones with over 1000 exact searches a month, my plan, however, is going for very long keywords and choosing 100-150 keywords that have like 100-500 searches month, of course they have very little competition so they will take less time and effort to rank for.

I am choosing a keyword, and writing an article with a nice kw density. My question is does anyone here recommend doing it, have you had great success with this method? I am fairly new to the SEO game, so I'd like to get some insight.

In my head it goes down to this, if you have 50, 100, or more articles with keywords that are searched for 100-300 times a month that can add up to quite some good traffic numbers. I'm talking 10k-20k/month.

Does that seem like a good plan or am I wasting my time?

Thanks.