This.
ROI isn't everything.
I'd rather get 200% ROI on $50000 than 2000% ROI on $500.
Lower rankings will always get better ROI by definition, because you'll pay less for them, for what will usually be the same value leads. The problem is you don't get as many leads.
^^ I aint mad at cha, and your still my friend. But I call utter BS on this statement.
For one, you can get same and more clicks from average position 5-7 that you can for average position 1-3 in PPC. I've seen it time and time again over the years. With that in mind, you are going to get the same lead volume or more with the exact same LP in the test.
^^ why? Well if your pulling in more clicks with the same LP as a position that getting less clicks ( it happens even for the top 3 ), you'll have more chances at a conversion by default. Also, when your at lower positions, you're removing a lot of tire kickers and people that have already seen the other BS competitors of yours so many times they are more qualified too, learn to write your LPs for that fact. No more wasting clicks on people not interested yet just because your ad was #1 position.
So just because you think your paying less ( not always the case with QS and other factors in the mix ) for a lower position, dont think your getting less leads.
The problem with your math above is you assume less clicks/leads at a lesser average position then a top position.
^^ I can see some verticals where this can happen ( maybe like payday loans where someone doesnt give a shit where they get their loans because its all cookie cutter ), but when you run in ecom niches and other areas where the seller can be the differentiation factor in a sale against a competitor.. there is a whole other world out there.
Bottom line, it depends on the niche. Dont generalize lower position = less leads/clicks because its not so.