Keyword changes with Google Ext tool: HELP

Hi Warriors,

I have a really important question regarding my target keyword I have chosen for my ebook for helping parents with an addicted teen.


After EXHAUSTIVE keyword research 8 weeks ago using google external keyword tool and market samurai, I chose to target, "teen substance abuse" for my ebook on helping parents with an addicted teen, and bought a url with that name in it.

Here's the kicker and what has prompted me to ask this question. Now that I have launched my book, written 6 articles and a squidoo lens targeting "teen substance abuse"- when I check on google's keyword tool and market samurai - it shows virtually zero traffic!

I do not want to put myself in a position to target a keyword that will not bring me to success. What do you think?

Here are other url's I currently own that I could switch it to if y'all (Texan) think that would be a help: teenagealcoholism.net, teenagealcoholism.org, teenagersdrugabuse.org (this one is too competitive), teenagesubstanceabuse.net, family-intervention.org). I ended up picking the teen substance abuse because it can refer to both drugs and alcohol which my book is about and it wasn't as competitive as some of the others. Family intervention gets good traffic although it is not as specific.

My first question is- should I switch my url and the main keyword I am targeting for my addicted teen book?

What would be the best main keyword I should target (market samurai showed teen substance abuse to be superior to teenage substance abuse- but now that is reversed).

My second question is: What are the main criteria to make a good keyword list. Should I concentrate on 5-10 main keywords? Is it finding keywords that are 3000-20,000 a day?

Thanks