A couple of interesting points come up from this Techcrunch article. Its something I wrote about when the Dell 12 first came out. Dell are now discontinuing the Mini 12.
The Dell reasoning:
Dell say: “It really boils down to this: for a lot of customers, 10-inch displays are the sweet spot for netbooks…Larger notebooks require a little more horsepower to be really useful.”
The real reasons:
Firstly, a point missed by Michael in his article. With a 12″ screen the customer expectations are way higher than with 10″ screens leading to dissatisfaction and returns. Secondly, the point the Michael makes. By setting netbook pricing you lower profit margins! Finally though, you do something extremely risky. You lower pricing expectations for the more powerful devices with higher profit margins.