Remember last week when U.S. trends-tracking firm Nielsen reported that Android had passed both RIM's BlackBerry and Apple's iOS to become the number one mobile platform in the U.S.? Well, prepare for a little déjà vu. This week, a report from comScore is confirming the exact same thing. According to the measurement firm's numbers from January 2011, Android just edged out RIM to move into the number one position for the first time, with a 31.2% market share figure compared with RIM's 30.4%.

Android #1, Says comScore

comScore says that 65.8 million people in the U.S. now own smartphones, a number up 8% from October 2010. January was the first month to see Android move into the #1 slot, the firm says. Apple is in third place, with a 24.6% share, followed by Microsoft and Palm. Nokia's Symbian didn't even make the chart.

For comparison purposes, these numbers are slightly different from Nielsen's, but the overall trend is the same. Nielsen found that Android's consumer market share was 29%, while RIM and Apple were tied at 27%.

OEM Numbers Compared

Like Nielsen, comScore also looked at individual manufacturer market share. Here, it found that Samsung was on top with a 24.9% share, followed by LG (20.8%), Motorola (16.5%), RIM (8.6%) and Apple (7.0%).

These rankings are wildly different than Nielsen's, which found that RIM and BlackBerry led, followed by HTC in third place.

This may have something to do with the survey methodology - Nielsen looked at pospaid subscribers from November to January 2010, while comScore was looking at a 3-month average ending October 2010 vs. a 3-month average ending January 2011. It wasn't looking at just "postpaid" subscribers, either, but total subscribers (over 13 years old).

Again, both firms were focused only on U.S. data.

Feel free to comment below if you have other theories as to why the two companies saw such strikingly different trends on the OEM front.

Update: Here's what Nielsen's spokesperson tells us about the numbers. We're also asking comScore to confirm:

Our recently released figures (Nielsen’s) are *just* for the smartphone market.  That’s why RIM and Apple are on top in terms of manufacturer share.  I believe Comscore’s data is for the entire U.S. mobile phone market, including feature phones.  That’s why they report Samsung as being on top.

Update 2: comScore confirmed that's the case.

Mobile Content Usage Trends

Also included in comScore's report was a section on smartphone usage trends. Here, the firm found that 68.1% of U.S. subscribers used text messaging, 37.0% used browsers, 35.3% used apps, 25.3% accessed social networking sites or blogs, 23.7% played games and 16.5% listened to music.