Get Smart With Your Paid Keywords

Step One: Figure out the keywords that are always in the customer support emails from your competition.
Step Two: Buy those keywords for Gmail.
Step Three: Now you're advertising directly in the Inbox of your competitor's customers every time they are not 100% satisfied with the service they are currently receiving.

I haven't seen anyone doing this nor have I heard of it. If someone is doing this I'd be interested to hear how things are going and what kind of impact it is having.