Not enough data to give estimates

In plain talk I know that "Not enough data to give estimates" means that I shouldn't expect for a keyword marked thus to receive any hits.

I know too that Perry Marshall says to start out an AdGroup with "known good words," each of which is included in the ad itself.

Informed thus, I have taken HOURS to compile narrowly focused AdGroups of 20 or so words and ads that include each of the words. I am careful to include broad, phrase, exact, and misspelled variations, and exhaustive negative words.

When I run the Google traffic estimator, it's hit and miss. Sometimes I get all good words. Other times the traffic estimator says the whole group of words is "Not enough data to give estimates."

I started out by deleting words labeled "Not enough data...," because they weren't even good enough for "peel and stick." You know, where you "peel" off a word whose CPC is way high and "stick" it in a new adgroup that contains the too-high keyword verbatim in the copy of the ad itself.

Are all the HOURS of my excruciating keyword research for nothing? Should I leave the words in, that the traffic estimator determines are "Not enough data..." words? I have read that the traffic estimator's results can be way off too. I'm frustrated.

It seems like I'm taking way too long to compile my narrowly focused word groups. What's worse, my words so often seem to be "Not enough data..." words.