The number that matters is total show cost divided by qualified opportunities at day ninety. Everything else describes activity. If you track one figure, track that one, and compare it against every other channel you run rather than against last year’s show.
Why the usual metrics mislead
Footfall measures the hall, not the stand. Scans measure proximity. Impressions measure the organiser’s marketing. All three go up when the show is busier and tell you nothing about whether your week worked.
They persist because they are available on the Monday and the real number is not. That is a reporting convenience, not a measurement.
Count the full cost
Stand, build, travel, accommodation, shipping, the sponsorship line, and the days your team was not doing their other work. The last one is the one that gets left out, and it is often the largest.
Without it, a show that looked expensive and a show that looked cheap are not comparable, and neither is comparable with a quarter of outbound.
A worked example
Suppose a stand costs 18,000, the build and shipping 9,000, travel and accommodation for four people 6,000, and the four of them spend six working days each on the show and its follow-up. At a loaded day rate of 400 that is another 9,600, which brings the real cost to 42,600 rather than the 27,000 that appears on the invoice.
If the week produces fourteen qualified opportunities that still exist at day ninety, the show cost roughly 3,000 per opportunity. Whether that is good depends entirely on what the same money produces through your other channels, which is why the number is useless in isolation and decisive next to a comparison.
The figures above are illustrative. The point is the two lines teams leave out: the team days, and the ninety day survival of the opportunities.
Read it at ninety days, not at the close
The Monday after a show tells you how the week felt. The quarter after tells you whether it produced anything, because that is the window in which a conversation becomes an opportunity or quietly does not.
Set a target before you go and a review date in the diary, then look again at day thirty and day ninety. A show reviewed once, immediately, is reviewed at the only moment when nothing can be known.
What to do with the answer
A cost per qualified opportunity that beats your other channels justifies going again and probably going bigger. One that loses to them is not automatically a reason to stop, but it is a reason to change what you do there, usually by booking more of the week before arriving.
Most shows that underperform do so because the meetings were not booked in advance, not because the audience was wrong. That is a fixable problem, and it is cheaper to fix than the stand.