Str82u - 6:40 pm on Apr 4, 2013 (gmt 0)
OH MY, you mean you weren't using keywords at all? Yikes, I don't care what google says, they'd have to dump our sites in the toilet to prove keywords have no value. That's aside from the fact that other search engines can send healthy traffic too and ARE manipulated by or need the keyword suggestions.
The rule I've followed was G's guideline I think, "if the phrase doesn't occur on page, adding it in the meta-keywords is spammy" ~paraphrased
On the other hand.... you said 15?