Plone Conference 2010 - The Numbers

by Matt Hamilton on Nov 18, 2010
Filed Under:

So, I thought I'd write a post about the final financial figures for the Plone Conference 2010, and our budgeting, and how things went in the end. ie how accurate were we, and what all the costs were. The goal of this is to help anyone else who might in the future be organising the Plone Conference... or any other similar sized, similar nature Open Source conference.

For general background information on the event and its organisation, see the two previous blog posts:

The Initial Proposed Budget

Firstly we needed to decide how many people we would be getting to the conference. This was the hard bit (and the bit we ultimately got wrong). Last year's conference in Budapest got around 420 people, Washington DC before that got 350, and I think Naples and Seattle were similar numbers too.

The conference fee was lower for Budapest, to try and attract as many local people as possible, and there was a large travel bursary available from the Open Society Institue (OSI). We wouldn't have that bursary available and our fees would be on par with Washington DC and Naples. We did think however that we would get similar numbers of people as last year. In informal chats with people they reckoned that quite a few people would be interested in coming to the UK for the conference.

Based on this, we made the decision to hope for 400 attendees, yet be able to break even still with 300, and be able to cope with 500.

The original budget we put together when we submitted our bid came roughly to:

Total Fixed Costs £22,650
Total per-person Costs £90 / person
Normal Rate

£300 / person

Early Bird Rate £250 / person
Percentage of Early birds 50%
Sponsorship £21,000


This then gave us the following figures depending on how many attendees we'd get:

People Registration income Sponsorship Income Expense PF Fee Surplus
300 £82,500 £21,000 £49,650 £12,375 £41,475
400 £110,000 £21,000 £58,650 £16,500 £55,850
450 £123,750 £21,000 £63,150 £18,563 £63,038

The full proposal we submitted can be found on

One of the conditions of holding the conference is that the Plone Foundation gets a 15% cut of the ticket sales in order to help fund its activities.

The Reality

Well, as we went along we revised the budget and added and removed things. I also went to Budapest to meet up with Balazs and Judith the previous organisers to find out what worked and didn't work at the previous conference, this was invaluable and we learned a lot from their experience.

We moved the budget onto Google Docs, and if you are interested in seeing the actual budget by the time the conference happened... alas Google won't let anonymous viewers go back through the revision history, as it is interesting how it changed.

In short, we nearly doubled our fixed cost expenses from £22K to £35K as we decided to add more in to the conference. Don't worry, this was done with an eye on the budget, so was not a surprise, but there were plenty of things we wanted to add, and there was some room in the budget for it (see 'surplus' in the table above).

So the final expenses came out as:

Fixed costs
Other rooms £4,800
Office supplies £100
Nametags £128
A/V rental (speakers, mics, etc, for 4 rooms) £8,995
Videography £7,365
Stage graphics £728
Banners £80
Pint Glasses £1,436
Bags £751
Visual Identity (website) £2,000
Sprint Rooms £1,000
Training Rooms £2,400
Keynote speaker £4,500
Flights & Rooms £909
Networking / Server £854
Total fixed costs £35,295


And the per-person costs:

Per person costs
Delegate rate/lunch (thistle hotel) £35
Conf dinner rate £24
T-shirt / person £5
Bags / person £2
Paypal fees (approx) £13
Total per person costs £79


The increase in fixed costs can be quite justifiably explained. We hadn't figured in the cost for a guest keynote originally. Whilst it was expensive, that figures does include a £1,000 donation to the Bloodhound project. And I think everyone who was there will agree they keynote was absolutely amazing.

We also decided to spend more on A/V and staging, and again I think that was very well appreciated. We had most of the video of the talks up by the end of each day, and the stage did look amazing.

Originally we had thought we could get the sprint and training locations donated to us by a local media centre, but in the end didn't think we could fit everyone in, and since we would be putting all the wifi infrastructure in the hotel anyway, it might just be easier to stay there for the training and sprints. This cost a bit more money, but allowed people to keep sprinting as long as they liked in the evening.

The Final Count

At the final count we had 285 people at the event. Whilst the event itself went very well, I have to admit I found the final turnout a bit disappointingly lower than we expected. We were quite a long way off our mark of 400 people, and whilst the economy might not be great, I know there were a quite a few of the 'usual suspects' that did not attend in the end. We had contracted with the hotel for a minimum of 300 people at the event, so we ended up losing a bit of money on that. We did however have a very good spread of people, from a total of 33 different countries in the end:

64 United Kingdom 5 South Africa 2 Romania
29 Germany 5 Japan 2 Czech Republic
27 United States 5 Denmark 1 Nicaragua
27 Belgium 4 Slovenia 1 Luxembourg
22 Netherlands 4 Poland 1 Jamaica
17 Italy 4 Finland 1 Ireland
12 France 4 Australia 1 India
11 Spain 3 Greece 1 Hungary
9 Switzerland 3 Brazil 1 El Salvador
7 Austria 2 Ukraine 1 Canada
6 Norway 2 Sweden 1 Argentina


The final financial figures at the end of the day when all was said and done are:

Total Ticket Sales £69,500
Sponsorship £16,535
Total Expenses -£72,256
Bloodhound donation -£1,000
Plone Foundation donation -£10,425
Net Profit £2,354


The conference is run as a not-for-profit event, and our plan was to keep the costs as reasonably low as we could, whilst still delivering the best conference we could. So overall, whilst we definitely covered our external costs for the event and had an amazing time in the process, if we'd have had around 50 more people attend then we would have covered the cost of our time a bit more.

But... would we do it again..... YES! ;)

Elizabeth Leddy
Elizabeth Leddy says:
Nov 18, 2010 05:09 PM

Thanks for posting this - fascinating and good info for those of us looking to host in the future!

Matt Hamilton
Matt Hamilton says:
Nov 18, 2010 07:33 PM

Well, the idea was to try and give out as much information as we wish we had at the start of our bid. Hopefully this will be of use to those putting in bids for 2011.

Wyn Williams
Wyn Williams says:
Nov 18, 2010 05:13 PM

First off, great conference, I think the way Netsight setout the budget in terms of break even point, hoped for guests and can cope with was def a model for others to follow
Any time organizers of a conference like Plone's turn around and say at the end of the conference they would do it again means it was done well - It would be nice to collate all the various conference organizers experiences into a conference org guide.

Of course, having people like the ones on your team available is also key !

Matt Hamilton
Matt Hamilton says:
Nov 18, 2010 07:35 PM

Thanks Wyn :) Indeed having a good team is one of the key points. If it wasn't for the fact I'd like to go somewhere else next year, I'd certainly be happy to run it again!

I'm hoping we can run some kind of regular event in Bristol now, maybe an annual sprint. The Beer & Pie sprint ;)

Armin Stross-Radschinski
Armin Stross-Radschinski says:
Nov 18, 2010 06:08 PM

Thanks Matt for your open approach to share your calculation model and the final meeting of the goals. First the conference was amazing and we have to tackle every year different circumstances. There are conference organizers out there, that can tell you less successful financial stories, even if they planned well. So your estimates were well done. The result pays back. Giving the Foundation that refund of £10.000 can make you proud anyway. We should make more of that confs ;-)

The count of attendendees is not the measure at all. It is the usual up an down. If you see there was the upcoming South America Event, you know that nobody can split up in too much copies of himself. And we have a global pulse that is hopefully coming up next year again.

In Germany we were thinking about a upcoming Plone conference too, but next year the DZUG is focusing on a triple slot event together with the Python and Zope guys. The DZUG Conference is the only really big event focused on our base technology Zope worldwide and we should keep this, like the Zope Summit this year, on our schedule first.

I am curious where we meet the next time. Plone is organized very well and if we stay restless, we may have some additional time together whatever route we take together, even after Plone has transformed into something else in the future.

I enjoyed every day and the spirit in your beautyful town.


Matt Hamilton
Matt Hamilton says:
Nov 18, 2010 07:40 PM

Armin, thanks for your comments. Yes every year there are different circumstances, and so it is not very fair making direct comparisons based on numbers of attendees. As someone said to me, managing to get 285 attendees at *any* conference during this economic climate is a pretty amazing achievement.

It does make me very proud to be able to make a £10,000 donation to the Plone Foundation. We also made a donation to the Bloodhound Project to help them with their achievements, and we are going to donate the 100Mbit wireless link we used for the link to the conference venue to Bristol Wireless, a local non-profit which get connectivity into various community centres around the city.

I am really hoping to get to DZUG one year, maybe next year. I was hoping to this year, but ran out of time.

Commenting has now closed on this post.