[More information and a full transcript of this advert can be found in our FB group]
The 'financial advertising' advert was one of a number of Ogilvy's long-form advertisements that were used as a means of demonstrating their expertise and providing industry-specific social proof. The long-form advertising was a technique widely avoided by many in the fear that they were "giving too much away" (a ridiculous proposition when measured against our current understanding), but the technique was a defining feature of Ogilvy's ads while others were trying to be cute.
Of interest is Ogilvy's line "the more you tell, the more you sell" (top right). While Dr Charles Edwards might have said it first, Ogilvy made it famous. There's no question that long-copy sells if you're selling the right product in the right way (sadly, something brokers just do not do).
When Ogilvy and Mather printed the article they essentially took ownership of the principles discussed despite the fact they were commonly applied by others at the time (their points of diff were shared by others, but Ogilvy were the ones talking about them). Ogilvy took the long-form approach when others were printing small ads that weren't nearly as readable or compelling.
If you write long form, tell a story. Stories master.