Using a composite of data from both comScore and Nielsen, Asymco's Horace Dediu has estimated Nokia is selling just 82,500 Lumia handsets in the US a month.

Dediu has compared Nokia's Windows Phone share reported by both parties to total smartphone sales figures, deducing that the Finnish firm sold around 330,000 Lumia devices during a four month period.

Knocking Nokia

"Nielsen's total Windows base adds up to 4.5 percent while comScore reckons on 4 percent," states Dediu in a blog post.

"Within that total, Nielsen breaks out 3.2 percent for Windows Mobile and 1.3 percent for Windows Phone. Within the Windows Phone total, HTC and Samsung are shown as having 0.5 percent and Nokia 0.3 percent.

"If we then use comScore’s figure for total smartphone users - 110 million - then the data would suggest that there are 330,000 Lumias in use in the US. This would have been accumulated over a sales period of about four months."

Interesting, however, is Nielsen's assessment that Nokia's lead over its Windows Phone rivals is so slight.

The launch of Nokia's Lumia 900 was met with reports of shortages ahead of its later debut on European shores, with CEO Stephen Elop having suggested early Lumia-wide sales in the region had "exceeded expectations."