Users Decipher Serial Numbers to Estimate Nexus 4 Sales
Rough estimates indicate just under 400,000 units sold so far.
Despite launching several months ago, Google's Nexus 4 smartphone is still pretty hard to find. The company's first device developed in collaboration with LG has suffered from supply problems from the beginning. Each time the phone becomes available on the Google Play Store, it sells out within a few minutes. Even those that do manage to snap one up are met with abnormally long wait times (as long as eight weeks) for delivery. So, the phone is in demand, that much we know. But how many has Google sold?
Neither Google nor LG has revealed any sales information, nor are they talking about production volumes. However, one user on the XDA Develops forums has used Nexus 4 serial numbers to estimate how many units have been produced since the phone was launched in October. User draugaz says that using the serial numbers to infer production rate indicates roughly 70,000 devices produced in October, 90,000 produced in November, and 210,000 produced in December. That equates to around 370,000 units since launch.
If this rough estimate is close to true, it seems LG and Google have ramped up production considerably since the October launch, producing triple the number of units in December compared to October. Still, the device remains sold out on Google Play, which means production still isn't where it needs to be to meet demand.

So did this device, which is why it's still sold out to this day.
This isn't a low-demand device by ANY means.
Demand is not the problem, production volume was for the first two months after launch: only 70k and 90k units for Oct. and Nov. respectively.
This is much lower than most other launches of similarly hyped devices that often sell over 500k units/month for several months.
However, it didn't really matter because even if I still wanted one I wouldn't be able to. Hopefully something comes out soon, because my upgrade has been up for 2 months.
By releasing a phone that beats all other android pones in the value-for-$ segment by far, Google is competing with its own partners. It isn't wise to bite the hand that feeds you, so Google creates the hype without selling too many phones. Google isn't interested in making $ from Nexus 4, it only wants to create the hype, and show its partners that they need to do better (better value phones with up-to-date OS - which is what nexus 4 is). Google is basically telling its partners: "If you don't do a better job, remember that I have the potential to create a far better device than any one of you has right now, and you don't want me to do that and eat into your profits, now do you?" - hence the limited stock, because Google just want to bluff that it can eat its own partners for breakfast. Google wants as many partners as possible, and wants them to complete with each other, while google sits back and counts the $.