It's mostly just poking fun at the GAK ads that were aired on the hub during the episode. They replayed the commercial 4 times in a row on several commercial breaks. Hence the obsession of GAK two weeks ago.
So many Gak commercials... It was so strange to see so many commercials about the same thing after each other. Also, it made me realise how much better commercial breaks are here in Holland. Instead of many short breaks like in America, you get one longer break. There were so many commercial breaks in those two episodes when I watched the lifestream of the season premier. It were like six or seven breaks. If the season premiere would air with Dutch commercial breaks, you would have gotten only one commercial break or if you are really, really lucky, not even one at all. And also I don't think we have Gak commercials here.
Can someone PLEASE explain to me why the hell Bronies keep talking about Gak? Yes, there are Gak commercials on the Hub. No, they are not relevant to ponies at all. Not that I oppose to it, it's just bugging me that I don't know what this is all about = x =