Advertising?

I've been thinking about where to move forward with the proposed content for my next essay, last year I very broadly focused on advertising which I enjoyed to an extent, although felt my lack of commitment put a barrier on my connection with the subject.

OUGD201 Design for Print was a lengthy module with a resolution looking at unusual/unexplored product-brand collaborations, I ended up focusing on Nike branded product and through that, at a lot of their advertising styles and techniques. I came across this .PDF document discussing the rise of their 'Just Do It' advertising campaign phenomenon, it sparked thoughts about my previous essay and how I could expand on and home in on a much more specific area of advertising.