Every piece names its sources. Where we relied on somebody else's estimate, we say so, and where we did the arithmetic ourselves we show it.
The advice is always the same: one goal, form up top, few exits. So I took the pages Google itself puts first for that advice and checked whether they follow it.
A client's developer told us the conversion tag was gone. He had checked the way everyone checks, and the way everyone checks does not work any more.
Somebody asked why their cost per click kept climbing when they had not touched a bid in a year. I did not have an answer, so I simulated the auction.