Just to ask, where have you seen this? As in, what city and district?
I was in several computer markets (as you know, "store" does not quite describe the situation in a Chinese building of small shops) last weekend. I saw no linux.
That is not only in my city; but in the many I visit. If there is an Ubuntu store or Kosk in Shanghai I would like to know where it is, just so I can visit it (I am not in Shanghai; but, it is only a few hours travel away). I will also be in HK next week, near Wan Chi, If there are any in that district I would also be interested.
I don't know where exactly, and even "thousands" scattered about China isn't particularly common. Admittedly, my information comes from statistics quoted in a presentation (alongside some pictures of the kiosks).