Dual sim phones are undeniably an important part of the mobile device industry, especially in the Middle East and East Asia where it's common for most people to have multiple lines. The issue however arises when you decide which phone gets to get a dual sim variant and which doesn't, I personally am not a fan of allocating the lower end of the device spectrum for dual sim phones; and here's why.
The reason most people carry two lines/numbers (outside the US) besides the need for a business phone and a personal number is usually a cost cutting measure. In the Middle East for example there's a huge variation between the price per minute/second for a call to the same mobile network, as opposed to a friend on a different network, in fact sometimes same network calls are practically free (keep in mind we're talking about pre-paid lines with no expensive monthly/yearly commitments).
Therefore it's become common practice in the area to carry two phones or two lines, to keep the cost of your communications down (especially in the younger/college aged community). Personally I don't bother with the hassle of having to lines for a number of reasons mainly that it's not worth the hassle of having to carry two phones at all times and charge them up etc. (I'm a very lazy guy).
For the sake of argument though, let's assume I wanted to purchase a dual sim phone to cater to my needs, and avoid the hassle of having to carry two phones at all times, what are my options? Instead of having the option to carry one "good" (high end) phone and a second cheap $20 phone, my options are instantly limited, and the selections aren't very nice.
Playing along with Nokia's strategy of dual sim phones, technically my only option would be to pick a phone from the Asha lineup (S40) or from the S30 Dumb/Feature phone segment, not the prettiest of selections for a guy who likes to do a million things on his phone. This is essentially the problem, why is it assumed that a dual sim phone should be a low end device? This has been Nokia's strategy for a while now, even with S^3 which was also never graced with a dual sim phone.
Samsung have partially gotten the equation right, with their "duos" line up which offers a decent selection of features with the dual sim capabilities; so when will Nokia decide to do the same (or even one-up them)?
Recently Qualcomm have announced their latest series of Snapdragon 200 processors which bring (you guessed it) dual sim support to Windows Phone, however once again if you read the specifications of the chip you'll see that this isn't designated for your high end (lumia 920/820- like) device. Most probably we'd end up with a variant of the Lumia 520 9or if we're lucky the 620) with dual sim capabilities, and that won't really cut it.
Why shouldn't you make a dual sim variant of your flagship (or runner up) phone? I understand there are related costs to creating another variant of a device in production (besides allocating the machines and factory time); but a flagship device is supposed to be your best and biggest hit with your consumers right? So why should you alienate a portion of your consumers and force them to buy an inferioirly specced device, or god forbid drive them into your competitor's arms?
*keep in mind that the biggest argument to advocate low end dual sim devices, is that they are more common with the people looking for a cheaper solution, which is true; but at the same time people with *enough* money to spend also want a dual sim phone (hello business men!).
what do YOU (yes you!) have to say on the topic?