KEYWORDS
When initially setting up your campaigns, DO NOT go to some keyword tool and dump in a gazillion keywords into your adgroups and campaigns– unless you want to boast about how many terms are in your keyword portfolio. The majority of these terms, scored by whatever techniques are going to be junky and low volume– and the engines will penalize you for it. Rather, what I do is hand pick just a few terms per ad group and then borrow ads from competitors that are already bidding on those terms. Sounds simplistic? Well, it is– but it works. Make sure you group your keywords tightly, so they all reflect the same user intent. The engines will choose one of the ads from that ad group to show, so make sure that each keyword is just as relevant for the ad you show.