A cheap cost per registration looks good on a dashboard. It doesn't tell you who actually registered, whether they turned up, or whether they were ever worth having in the room.
Until you find out who registered.
A junior professional from a company you've never heard of. A student. Someone who registered because the event was free. Someone who lives 4,000 miles away and has no intention of travelling. Or, ideally, a senior decision-maker from one of your target accounts who could spend six figures with an exhibitor.
All four are technically conversions. They are absolutely not worth the same amount. And yet event marketing dashboards have a habit of treating them that way.
Registrations are easy to count. Value is harder.
This is where B2B events get interesting. For a lot of businesses, the registration is only the beginning. The real value might be the attendee actually turning up, the attendee being from the right company, the attendee having the right job role, the attendee visiting an exhibitor, the attendee becoming a sales opportunity, or the attendee generating revenue for a sponsor.
“WE’RE GETTING REGISTRATIONS AT £50.” THE OBVIOUS NEXT QUESTION: “£50 FOR WHO?”
Because a £50 registration from the wrong audience can be more expensive than a £150 registration from the right one.
Google and Meta are very good at finding people who are likely to do the thing you've told them to optimise for. Tell a platform to get you registrations, and it will get you registrations.
But it doesn't inherently know that registration number 4,271 is a senior buyer at a target account and registration number 4,272 is someone who clicked a LinkedIn ad because the event looked interesting. Both completed the same form. Only one might be commercially valuable.
This is where B2B paid media gets more complicated than simply chasing the lowest CPA.
Let's say Campaign A delivers 1,000 registrations at £50, for a total spend of £50,000. Campaign B delivers 500 registrations at £100, for the same £50,000. On the surface, Campaign A has won. Twice the registrations for the same money. Then you look underneath the numbers.
| Campaign A | Campaign B | |
|---|---|---|
| Registrations | 1,000 at £50 | 500 at £100 |
| Total spend | £50,000 | £50,000 |
| Attendees | 200 | 350 |
| Target accounts | 30 | 120 |
| High-value prospects | 10 | 45 |
Suddenly the conversation looks very different. Campaign B didn't fail because its CPA was twice as high. It found more of the people the event actually needed. Cheap isn't the same as efficient.
This is particularly important for events with exhibitors and sponsors, because the value of an attendee isn't necessarily determined by the ticket price. It can be determined by who else wants access to them.
A delegate from a highly relevant target company could be considerably more valuable to an exhibitor than five low-intent registrations. A room full of the right people creates value for everyone else in the ecosystem.
That means attendee acquisition isn't just a volume game. It's a density game. Can you get enough of the right people, from the right companies, into the same place at the same time? That's a very different paid media objective from “get as many registrations as possible.”
CPA still has a place. It just shouldn't be the end of the conversation. Look beyond the registration and start asking four questions.
Job title. Company. Industry. Geography.
A registration that never turns into an attendee isn't worth the same as one that does.
Did they match the audience your exhibitors, sponsors or sales team actually want?
Engagement, meetings, opportunities, pipeline, revenue.
The exact metrics will depend on the event, but the principle stays the same. Measure the thing that creates value, not just the thing that's easiest to track.
Once you know what a valuable attendee looks like, you can start making better decisions. Maybe one market produces fewer registrations but significantly more high-value attendees. Maybe one job-title segment costs twice as much but delivers four times the commercial value. Maybe LinkedIn produces a higher CPA than Google but reaches the companies you actually want in the room.
Maybe a campaign that looks mediocre at registration level becomes one of your best campaigns once you connect it to attendance and downstream outcomes.
That's when paid media starts doing something more useful than simply filling a dashboard. It starts helping you decide where the next pound should go.
Fewer, better registrations can be exactly what an event needs. If you've already filled your campaign with low-value conversions, throwing more budget at the same audience can make the numbers look better while making the event commercially weaker.
The objective isn't more people. It's more of the right people. And those two things can have very different costs.
There isn't a universal answer. It could be worth £5. It could be worth £500. It could be worth considerably more if that person represents the right company, the right opportunity and the right commercial relationship.
Which is why the question shouldn't really be “what's our cost per registration?” It should be “what are we willing to pay to get the right people into the room?”
That's a much harder question. It's also a much more useful one.
94% of buyers rank their preferred vendors before ever speaking to a seller. Why the dark funnel matters.
Read →
Why growth needs unit economics, not a rigid ROAS target that switches off your next customers.
Read →
Traffic is up 25% and revenue is flat. Before blaming the traffic, ask what it was meant to do and where the journey can work harder.
Read →This is what giving a damn looks like in practice. Tell us what's not working.