This drives me crazy. I was at a dealership today who complained they only saw a marginal increase in leads after they switched PPC vendors and significantly increased their budgets. The PPC company then came back asking for more money because the impression share was low.
It turns out the PPC company was buying all the keywords you could possibly think of (including branded keywords) instead of tailoring the keywords you buy to the budget.
Instead, take a holistic approach. Look at the big picture. Let organic listings get all the traffic they can. Use paid search to buy in places where you can't rank organically or where competitors are buying ads.
