This argument is trash. Having more products doesn't magically spawn new customers out of nowhere (if it did, what business sense does it make to limit it to 3 products like Apple does?). More likely, the Samsung customers are distributed among the different products (or perhaps the different Android customers are distributed among all the different Android products).
Sure, a certain portion of their customer base are probably based on the fact that there are many options but only an Apple fanboy could try to twist customer choice as something negative.
Also, it's funny how the anticipation for the next iPhone is suddenly a problem. Earlier years the sales went on like normal and it was explained with how the average customer didn't know that a new model was around the corner, but now the lower sales are blamed on the idea that everyone suddenly knows this. It changed that dramatically in only a year? Call me skeptical.
Basically every country besides the US (as I understand it)
I'm afraid you are mistaken. It's not necessarily a larger number of products that allows for more customers, although it probably has an effect, but a range of products available at a wide range of prices. You can supply products to every demographic when your products span the full range of prices.
Yes you can buy an iPhone 3GS for free with a contract. But 1. it's not actually free on a contract, and 2. you cannot pick up low cost iPhones anywhere near as widely as you can with Samsung phones.
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Instead of using number of "smartphones" shipped as some conclusive indication that Apple and the iPhone are falling out of favor in the public eye, why not turn to research that addresses that directly. Last time I checked, Apple was a far more popular and satisfying brand. Of course this may have changed very recently, but I don't think this is the information we should be using to make that assessment.