tedster - 6:19 pm on Mar 20, 2012 (gmt 0)
The idea really has two parts. First, the search phrase does show up as a top Suggestion, early on as someone begins to type that phrase. Traffic is definitely hurt if your keyword phrase does not show up at all or is toward the bottom.
And the second part of the idea (basically it's being assumed here) is that you want to be ranking well for that phrase.