Its nationally recognized too, and every grocery store and stationary shop has a big display devoted to Pepero. I went into one of my favorite stationary stores for a pencil case, and half the stock had been moved or put away so that the length of the store was covered in different styles of Pepero, as well as cards, bags and baskets, and decorating materials for dressing them up as gifts.
The idea is that couples will buy Pepero sticks for each other, but it's also turned into a gift giving day for friends and teachers too. Before each of my lessons today, I asked my students "What did you do yesterday?" (because we're learning several expressions using past tense), and in every class they were shouting "Pepero! buy/bought Pepero!" Do I think Lotte's an evil corporation turning children into consumer slaves? No. I'm not that melodramatic. The whole concept is actually pretty fun. I mean, you can get about 4 boxes for the equivilant of $1, less if you choose to give larger individual Pepero sticks.
It's mostly just the energetic spirit of giving, and as holidays go, this is by far the cheapest and most random. It also worked very well for English class, because shy students were given a catalyst to come up and speak to me personally using some simple English phrases ("Here you are," "This is for you!"). Adorable. It was a very good day to be a teacher. I think I shall be happily munching these sticks for a long time.