You may be disappointed if you choose the amazon link. I had a hard time finding any candy in that box. It seems to be made up of mostly senbei (rice crackers) and Umaibou (think Cheetos in a stick). The seaweed makes a lot more sense when you realise that it's savoury, not sweet. For some reason, quite a lot of Japanese children do not like sweets. I don't think any of my friends kids like sweets. Korean style flavoured nori seaweed is a really popular snack (especially with really young children -- 1-4 years of age).

But, getting a bit more on topic, that amazon link is "dagashi", which is just inexpensive snack food. It can contain candy (in that box I notice "Milky" which is a hard candy), but things on the same level of potato chips would be in that category. I don't know for sure, but I think CandyJapan sells only candy. The "It'sugar" link seems to be much more similar.

I'm going to guess that his target market is people who have an interested in Japan (possibly through anime) and would like to try an assortment of Japanese candy. I think his home page does a lot better job of explaining the product than the ad did, so possibly it's something to think about in the future.