RegDCP - 6:58 pm on Sep 6, 2012 (gmt 0)

I have always wondered if Matt Cutts' comment was accurate when he said that they don't use it for search ranking.

Properly used metas are normally a part of database markup.
They are "Information about information.", which means they accurately describe the content of the page.
This should be as concise as possible.

The text strings in Meta tags are weighted.
The fewer the words, the more weight each carries.
The closer to the beginning of the string, the more weight.

When MC told us that the KW tag was not used, I doubted that Google would throw away such a valuable part of an indexing process.

I suspected that this tag was still of great use in determining over-optimization.
If it was concise and accurate it passed the test.
If it was stuffed with every keyword imaginable related to the content, the page got a slap down.

Are the results repeatable?
Can you take another low ranking page, add a kw tag, and get an improvement?