A recent report from analyst firm Kantar Worldpanel ComTech shows that the iPhone 5S is outselling the 5C at roughly a three-to-one rate. However, the 5C is still helping Apple eat into the marketshare of mid-end smartphones, where Samsung and LG dominate with devices running Android, in developed countries.
According to the report, 80% of new 5S owners are former iPhone users, while the iPhone 5C is attracting 50% of its customers to jump ship.
A few things to note: first, there is no way to get absolute numbers from this data set, meaning that conclusions are hard to draw. Second, this is an analyst firm, and as such the data may not be accurate in almost any way. Remember, these analyst firms do not necessarily work for you. Last, the iPhone 5C may well be drawing users from a number of platforms. While Android is the most popular base OS, Blackberry, Symbian, and even Windows Phone have footholds in various locations. A colorful, powerful iPhone may well attract those users.
Still, this much is easy to say: both devices have proven to be incredibly popular with buyers.