Jlee:

Nice to see an illustration for #1 and #5. Did the illustration for #5 come from a WordStream product? Just wondering.

Here's another question on point #1.

Since 100 keywords for 1 Ad Group weakens quality score (and increases CPC while decreasing placement in the ad) and multiple ad groups with much smaller keyword groupings improves quality score, it raises a question for me.

Bad: 1 Ad Group with 100 keywords.
Good: 10 to 20 Ad Groups with 10 to 5 keywords per ad group.

If quality score improves with many targeted ad groups, should those targeted ad groups also have customized landing pages?

Learning PPC on my own just through books and blogs, I've always thought that PPC ads convert better with customized landing pages.

It seems like the good advice to multiple ad groups would suggest using customized landing pages for those ad groups also for better conversions, which in turn would raise the cost of the campaign. Am I over thinking this process?

A fine article, thanks again.