Wow, this is indeed very cheap, actually cheaper than domestic data rates in some EU countries. But the following sounds like this option is not only reserved for postpaid customers but even subject to longterm agreement so you can't unsubscribe until your contract ends:
Are these conclusions correct?

Yes.

They also have a more expensive option which can be turned on and off at any time: Tarieven mobiel internet in het buitenland met Travel & Surf - T-Mobile it gives you 100MB at unlimited speed and then throttles to 64kbps. €14,95, valid for 1 week.
This option is actually also available for prepaid customers, but for prepaid it isn't unlimited (after 100MB you pay the full price again).

Oh, and there's also Vodafone, which has a day package of 35MB for €2, which also includes 20 incoming minutes, 20 outgoing minutes and 20 SMS. So this would also be a little cheaper than Medion. Alles-in-1 op Reis

-is this valid for prepaid customers? i think is only for postpaid customers.
-how much is tha data rate after you run out of the 35mb?
-you can only activate it once per day?



the cheapest bundle choise for european data roaming is europasim, 100 MB for 2€ per day, that's just 0.02€ per mb..
europasim (on vodafone italy network) now offers 2packages for 33european countries , including some non-EU countries such as Ukraine, Moldova
100 MB for 2€ per day (APN mobile.vodafone.it or iphone.vodafone.it)
150 MB for 6€ per day (APN web.omnitel.it)
http://www.europasim.com/epages/6335...ectID=38780738

Yes Inquisitor and I were talking about contract offers now (to see if they are any better than prepaid).