James Herbert, Co-Director at Effectief Altruïsme Nederland and EAGxAmsterdam Team Lead

EAGxAmsterdam 2025 took place on 12–14 December at B.Amsterdam, bringing together 517 attendees from across Europe. This is a brief write-up of what went well, what didn't, and what I think other EAGx organisers can learn from it.

The headline numbers:

• 517 attendees (up 36% from 380 at EAGxUtrecht 2024) — one of the largest EAGx events in recent years, behind only EAGxBerlin 2025
• €387 cost per attendee (target was €520; 2024 was €586)
• 10 reported new connections per attendee (target was 10, 2024 was 10)
• 906 applications (34% above target)
• 57 GWWC pledges (26 full 10% Pledges + 31 Trial Pledges) — the strongest pledge outcome of any EAGx to date, and ahead of every EAG and EAGx event until that point except EAG NYC 2025. GWWC estimated this represents ~$2.9M in expected lifetime giving ($436K counterfactually adjusted).
• NPS of 63 (mean recommendation: 8.86/10)

Budget

Cost per attendee came in at €387, down from €586 at EAGxUtrecht 2024 — a 34% improvement while serving 36% more people. 

The budget is dominated by venue and catering (~70%), with contractors (~23%) the next largest line. Compared to 2024, venue + catering fell significantly despite the larger event, contractor costs rose as we brought on a more experienced team, and paid advertising roughly doubled from €2,599 to €4,176 — a modest increase that drove outsized returns in applications.

The case for investing in marketing

The single biggest change from 2024 was investing in professional marketing. We worked with two external teams: one for strategy and creative assets (not so creative), and one for Meta campaigns (Amplify). This was an investment, but I think it was clearly worth it.

The result: 906 applications versus 570 in 2024 — a 59% increase. We reduced cost per attendee from ~€586 to ~€387. More people, better cost efficiency. The marketing spend paid for itself many times over by spreading fixed costs (venue, AV, catering minimums) across more attendees.

I'd strongly encourage other EAGx organisers to consider professional marketing support, especially for Meta campaigns. The EA community's organic reach has limits, and if we're serious about growing the pipeline of engaged people, we need to invest in reaching them. Our experience suggests you can do this without sacrificing quality — 53% of our attendees were at their first EAGx, and quality metrics held steady or improved.

Content highlights

I'm really proud of the programme Ricardo built this year. We built a lineup that combined international EA celebrities (Benjamin Todd, Michael Plant, Bob Fischer, Sjir Hoeijmakers, Stien van der Ploeg, etc.), stalwarts of the regional community, and speakers with significant standing outside EA — Sarah Bouchie (CEO of Helen Keller Intl, a GiveWell top charity, at her first EAGx), Arthur Baker (Chief of Staff to Nobel laureate Michael Kremer), Susi Snyder (ICAN, 2017 Nobel Peace Prize), Dirk-Jan Koch (Director of the Dutch Advisory Council on International Affairs), and Paul Meerts (former Deputy Director General, Clingendael Institute). Talk satisfaction rose from 4.27 to 4.40 year-on-year.

We also experimented with a "Talk + Fireside Chat" format — a short talk followed by a moderated conversation — and it scored 4.93/5 on Swapcard, compared to 4.26 for standard talks. I'd recommend other organisers try this.

Michael Plant wrote publicly afterwards about his experience, noting he left "much more optimistic" about the EA movement's direction. 

What didn't work

Being transparent about the shortcomings:

• The December date was unpopular. Satisfaction with the date dropped from 4.30 to 4.07, with attendees citing exam and holiday clashes. We'll look at this for next time.
• Venue noise was a real problem. The 1:1 spaces were too loud for meaningful conversation, and sound leaked between rooms. We had more attendees than expected.
• Swapcard remains frustrating. Scored 3.74/5, with increased negative mentions in qualitative feedback. Bugs, crashes, confusing navigation.
• Female attendance dropped from 40% to 35% of survey respondents.
• We missed scheduling BIPOC, Queer, and Neurodivergent meetups, which should have been in the programme from the start.

What I'd tell other EAGx organisers

1. Invest in marketing. It's the highest-leverage thing we changed. Professional Meta campaigns and early awareness-building drove a 59% increase in applications without compromising quality.
2. Hire experienced contractors. This made a huge difference for us. Our production officer, Chiona, is an events professional who also did EAGxUtrecht 2024 with us. Our admissions officer and volunteer coordinator, Kars, had done the same job at EAGxUtrecht — he knew the systems, the failure modes, and the pace required, and he handled 906 applications without breaking stride. Our content officer, Ricardo, has years of experience organising EA events and hosting conferences. And as mentioned above, we brought in professional marketing teams rather than doing it in-house. All of these people were simply excellent at their jobs, and I think that's because we hired for relevant experience rather than just enthusiasm or familiarity with EA.
3. Try the Talk + Fireside Chat format. Our best-received sessions used it.
4. Don't neglect venue acoustics. Noise complaints dominate qualitative feedback at events like these and they directly undermine the core value proposition: good 1:1 conversations.
5. Plan for GWWC pledge infrastructure early. Having a proper pledge booth was clearly high-impact — 57 pledges representing $2.9M in expected lifetime giving ($436K counterfactually adjusted) is a remarkable return.
6. Get photos back within 48 hours. We were slow here, which limits the social media momentum after the event.
7. Set clear goals and make sure everyone knows them. Alongside the main project management spreadsheet, we kept one simple document with the key targets. It meant everyone on the team — contractors, volunteers, the lot — knew what we were working towards. It sounds basic, but it kept us aligned.

Looking ahead

The Netherlands has hosted EA conferences since the late 2010s (before there was an EAGx programme). Most recently, we've had Rotterdam (2022), Utrecht (2024), and now Amsterdam (2025). Since rebuilding the event post-2022, we've improved on every metric: more attendees, better cost efficiency, stronger programming, and now a record-breaking pledge outcome. Survey data suggests the Netherlands has one of the largest national EA communities in the world (with Amsterdam being the largest hub city outside the UK/US), it's centrally located in a densely populated area,^[1] extremely well-connected internationally, and the results above suggest we know how to run these events well.

We don't yet have funding confirmed for a 2026 or a 2027 event, but we'd love to keep building on what's working. If you have thoughts on that — or if you're interested in getting involved as a speaker, volunteer, or sponsor — do reach out.

The full event report with detailed survey data and year-on-year comparisons is available on request. Thanks to Chiona, Kars, Ricardo and the marketing teams for making this event happen, to Jonathan Mannhart for the photography, and to our volunteers, speakers, and, of course, to the CEA events team for funding and supporting us.

1. ^{^}

   

   Turns out the Netherlands is really densely populated