Update (july 11): I ended up not buying my ticket to Berlin through Transavia. The tickets themselves were cheaper (EUR 0,00 instead of the promoted EUR 1,00), but the flying times were bad for me and the tax was high enough to make me reconsider. In the end I decided to spend my KLM Flying Dutchman miles on a free ticket where the tax (EUR 93) was lower than Transavia's (EUR 116) and the times suited my schedule better.
In case the cost of travel is holding you back from attending the upcoming EURO IA conference, here's a sweet deal:
Transavia.com is offering 1 Euro tickets from Amsterdam to Berlin on Tuesday, July 11 only (excluding quite some taxes, which you'd have to pay anyway).
Even if you're not Dutch but plan to attend EURO IA, this may be of interest since an international ticket to Amsterdam plus this 1 Euro ticket may well be cheaper than a direct flight to Berlin.
I intend to stay up on Monday and try to get in on the deal. You too?