The funny thing is that those little personalized surprises could be accomplished really easily if hotel chains used their CRM or frequent guest IT systems properly (and trained their staff accordingly). Actually, I think often the generic 'Welcome back' card in the hotel is nothing else- it gets prompted by a system generated remark that the guest has some sort of status with this chain (which would explain why so many properties 'welcome you back' when you've never stayed at that particular place before ).

But you could customize this in a much better way and that's where the real magic comes from. Let's say someone doesn't like chocolate but is a real boozehead (a certain Sydneyberlin might count into this group) and mentions this to one of a chain's property. This goes into the CRM system and each time another hotel of that chain wants to give me an amenity, this information should come up. Not all too hard really and some hotel chains/airlines really do this!