Yes, but the only adverts which actually work have a few vitally important things in common: not much text, clear design, simple colour scheme, and a *short* message which gets straight to the point. Look at any billboard advert currently on display for examples of this.
With the amount of (comparatively hard to read) text on the A9 poster, not to mention its small size compared to the 30-foot billboards around, I seriously doubt anyone walking or driving past would have time to notice much more than a man on stilts with a funny-coloured piece of cardboard strapped to him.
Adverts such as "Don't smoke" or "Buy this sofa" in massive lettering, black on white, in a clear typeface and with a single picture in the background, are far more effective. I'd suggest a similarly simple slogan such as "Treat yourself to a computer that works", a picture of the A9, and a link to a website where people whose interest is sufficiently aroused may find further information and all the geeky stats they could want, to peruse in their own time.
There's no point, as you say, writing an essay on a poster for the layman. The current poster is a visual essay.
I'd suggest having a read of the booklet which Richard Hallas (?) produced a few years back. I think it was sold via APDL. (Can someone correct me on this?)