The illusion of B2B business

Lot of us have now studied the lean business model by steve blank .
It says we need to find a problem , try to solve it and measure the impact of our solution so that we can scale.

In a b2b business - if we measure how many copies we are selling to measure impact - it ends up being a false vanity measurement .
we need to measure the impact on the end user .
so in reality B2B is just B2C .
B2B == B2C

B2B is just a distribution channel on top of B2C . the distribution channel can be quite powerful surely and help us during scaling but not during measuring problem - solution fit.
The impact on end user is true value that needs to be measured.cheers !P.S - I know it only gets harder now :)