In New Zealand Kobo and Sony readers are both sold in Whitcoulls, which is one of the big chain bookshops here. Whitcoulls sells ebooks too, but now it is really just a shopfront for Kobo, when you go to buy an ebook it takes you to Kobo to complete the purchase.
Sony doesn't have an ebook shop here, so on the
Sony NZ website they point you to Whitcoulls as the place to buy ebooks for your Sony ereader. Which means Sony is actually directing its NZ ebook business to Kobo.