The new Lumia 920, Nokia’s (NOK) flagship Windows device, is getting some decent marketing backing from leading American vendors. Best Buy (BBY) is hyping Windows phones at the top of its mobile phone page. Walmart is also promoting Windows phones at the top of its mobile phone page. The problem here is that the best-selling phone charts of both of these mainstream phone sites do not reflect any early impact by the Lumia 920.

If you click the Windows Phone banner on Best Buy handset page, it will ask if you prefer AT&T (T) or Verizon (VZ) — and then offer you the Lumia 920 or Lumia 822 as top choices depending on your carrier preference.

But BestBuy.com’s list of best-selling mobile phones with plans shows the Lumia 920 at #42. This particular bestseller list usually gives fairly high rankings for models in the pre-order and launch periods. The Sony (SNE) Xperia Ion is right now at #15, even though Sony’s brand is weak as a kitten and demand for Xperia models is light. The Lumia 920 is available for store pick-up on Manhattan on November 12th, though the vast majority of Best Buy stores list it as “unavailable.”

Why aren’t most Best Buy stores in New York carrying the Lumia 920 in its launch week? Why can’t it crack Top 40 if the new Sony smartphone — which 99% of US consumers do not even know exists — is at #15?

The mystery deepens at the Walmart website. The Lumia 920 is prominently pushed at the top of the handset page, with a stunning $50 special price bundled with a 2-year contract. But it’s a no-show in the Top Twenty chart of best-selling Walmart phones, a list that features such losers as the LG (066570) Extravert and LG Xpression. Both of these phones are not only abominations in the eyes of every English-language aficionado, but they are also selling at low volumes, with minuscule consumer awareness. Why hasn’t the Lumia 920 cracked the Walmart Top 20?

Maybe Amazon (AMZN) sales charts will provide us with some clues once the phone shows up. Right now, the Lumia 920 is not available at Amazon even though Best Buy and Walmart are taking orders, though Best Buy is not showing stocks at most of its stores.

This is a very odd launch for a flagship device that is going to have a decisive role for Nokia’s Windows project. It seems that Amazon Germany and some other sites in Europe have sold out of early 920 shipments in less than a day — so European demand could well run much higher than U.S. demand. It’s also possible that Nokia production is prioritizing Europe and Asia. US shipments could be spotty as a result. But I think it’s safe to say most industry observers expected a bit more muscular American launch for the phone.