While the 4 inch Apple iPhone 5s and Apple iPhone 5c together are selling very well, it seems that the smaller "mini" versions of Android flagship models are not; according to industry sources, sales of the Samsung Galaxy S4 mini have been floundering, although part of the phone's weak sales has to do with the generally weaker sales of the full-sized model...
Source: http://www.phonearena.com/news/While-a-4-inch-screen-satisfies-Apple-iPhone-buyers-Android-purchasers-want-more-than-mini_id48191
Source: http://www.phonearena.com/news/While-a-4-inch-screen-satisfies-Apple-iPhone-buyers-Android-purchasers-want-more-than-mini_id48191