..Rainer's comment is critical:
Update : a real life example I made last week.
For booking a hotel room I have used on of this portals some weeks agao.
2 weeks before my travel I went to this portal again, to check if there is a better hotel or better price.
So I found, that the same room is now cheaper. I called the call center of this portal, they were very nice, and changed the room to the lower price.
The day I went to this hotel there was a big surprise.
My hotel room was cancelled..
Why ?
The portal sent me and the hotel the new booking confirmation by email, and the hotel the cancellation of the old booking. But something went wrong inside the way from the job queue to the auto mailer.
The hotel received the cancellation after the new booking.
But the hotel was nice and gave me an other room.
As you see, even if you have a perfect portal in a cloud, there are still some magic things happening, which are hard to control. But when you go your way to the cloud, you have to keep in mind they are there.....
Happy Easter.
Rainer