I have also seen full-page AA ads in various Belgian newspapers (promotion: 10,000 addirional AAdvantage miles in C class; 5,000 in Y class). SN seems to be more discreet.
Well there was kind of a party, L Van den Bosche (or how do you write it? :-d) came to give a speech at the gate if I'm right. Anyway, there was a lot to do about the flight in the AA enviroment themselves. Employees received a special polo of with advertising for the JFK flight on and some other things (Got this information from my mother who works at AA )
I never saw annoucements from SNBA in newspapers but i know SNBA shall award you 5000 (economy) or 10000 miles (business) for a return flight to JFK, till end June, i think!!
The AA advantage is the same.