Dharmesh Shah says that the earlier in any sequence of words those keywords appear, the stronger the signal Google will receive.

FORBES: Magazine Article

More than anything else, I realized, it had to be boring to be crazy, to think the same sequence of thoughts and come up with the same set of bizarre conclusions, to voice those conclusions using the same words, several times an hour, day in and day out.

NEWYORKER: The Reptile Garden