Budget Sport viral marketing

I spotted some viral marketing for Budget Sport, a finnish sports dealer,  at Suomi24.fi (perhaps the biggest Finnish web discussion board).
(See the screen capture below)

Budget Sport background image

Budget Sport background image at Suomi24.fi

Hmm, well, interesting.

Image only shows at sports -related discussions. I didn’t know this was possible at Suomi24, obviously is.
Just makes one wonder how finely targeted such campaigns one could do... (And what does it cost!)