Jean-Frédéric, 27/06/2014 17:05:
Any ideas on how we could make sure this does not happen again?
To start with, it may be useful to make https://meta.wikimedia.org/wiki/CentralNotice/Calendar more precise and get an agreement with fundraising on what they will (not) run concurrently, e.g. by identifying what period is most effective for WLM and reserve CN fully for that part of the month.
Were multiple banners tried and do you have a way to extract some info on which was more effective? If the CentralNotice was turned on with the option which limits it to N views per browser, did this improve bounce rate?
Nemo