> Don't send all your traffic to your home page. Specific targeting for segments of your customer base will do much better than general messages that don't speak directly to anyone.

Can't vote this up enough. We had dramatic conversion success by creating specially targeted landing pages with a lead form embedded. Tying your keywords to specific, targeted content is essential to making the most of your campaign. The less a user has to hunt around to satisfy their search intent, the more easily you can make the most of their attention.