Awesome, best of luck to the ShopLocket team! I remember their post on HN awhile back about not getting into YC (http://news.ycombinator.com/item?id=3668469). It's fantastic to see them not only soldiering on, but thriving.
Am I the only one deeply annoyed that the article never even once mentions what the hell it is that ShopLocket does, how they make money, or to what ends they want to grow?
I'd say a simple definition of the "simple selling market" could be "sell online without opening an online store." I'd say https://gumroad.com/ would be their closest competitor at the moment.