These answers cover what the words mean.

Professor John Dawes of the Ehrenberg-Bass Institute estimates that something like 5% of business buyers are in the market in a given quarter, a rule of thumb that varies by category. So at any one time most of the companies that could buy from you are not looking, and they will buy later, often from vendors they already know.

Attribution assigns credit for an outcome to the touchpoints that preceded it, according to a rule you chose. Incrementality asks whether the outcome would have happened anyway, by comparing an exposed group with a comparable unexposed one. Attribution is a description of a conversion path; incrementality is a causal claim. Almost every reported media result is the first presented as though it were the second.

That the data provider asserts a consent chain exists back to the individual. Nobody downstream has necessarily verified every link in it. AdBuyMCP records the assertion in the plan's lawful-basis manifest along with the condition that comes with it: the supply chain must be framework-validated and the vendor attestation verified on connection. That is a condition you still owe.

Reach counts the distinct people or households who saw a campaign at least once. Frequency is how many times, on average, each of them saw it in a period, so impressions are reach times frequency. An AdBuyMCP awareness plan is sold by frequency, 3, 5 or 12 times a week, and states it as planned: each channel reports delivery in its own unit, and no UK service de-duplicates reach or frequency across sellers.