In the seventies Franco-belgian comics magazines like Spirou hardly contained any advertising, except maybe for their own album series or for the odd record player. Content mattered then as more than as a buffer between commercial messages.
And in case there was an ad in the magazine, it was very much tailored to the public, with products aimed at older teenagers (yes, they read comics magazines back then). This one is a very fine example, promoting the transalpino service, which allowed youngsters to travel by train with huge discounts. No wonder that De Mesmaeker, always a businessman looking for a deal, is quite cross that he can’t use it while Gaston, bewildered as ever, hasn’t even heard of it. Ah, simpler times.