Global sales by year of the pack in gamesWii Fit and Fit Plus (measuring Balance Board) and Kinect Adventures (Kinect).  The rank is include in parentheses.

2009  

8.8 million (4^th best selling)

Kinect not out yet

2010

Wii Fit Plus 8.6 million (6^th best selling game of 2010)

Kinect Adventures 7.2 million (7^th Best selling of 2010)

2011

Wii Fit Plus (Pack in for Balance Board) 3 million (22^nd best selling)

Kinect Adventures (Pack in for Kinect) 7.9 million (4^th biggest selling game of 2011)

2012

Kinect Adventures 4.6 million 8^th biggest selling

Wii Fit Plus 1 million 70^th best selling

When the Balance Board launched it was a great hit.  In 2009 it was the 4^th best selling game globally.  When the Kinect was released in 2010, it was still beating Kinect, but Kinect was only for sale 2 months in 2010, and still managed to come in 7^th place, just behind the Balance Board.

But, how the mighty has fallen, as the Kinect was the 8^th best selling game of 2012, while the Balance Board fell all the way to 70^th.  You can use the Balance Board with the current WiiU, so it still current.  Nintendo plans to have a WiiU Fit game out soon.

Has Kinect rendered the Balance Board obsolete?

Note:  These numbers are for total Wii Fit and Wii Fit Plus sales.  There are some duplicates, with people buying Wii Fit Plus the game only.  If someone has a way to get only the Balance Board numbers I would appreciate it.

Duh!! Balance board obviously is the winner.

Balance board! I used mine yesterday :D

Because I didn't see the point in going back much before it was sold – this is an idea I got from Jay520’s question has Microsoft taken the casual reins from Nintendo.  I am looking at trends, vs total sales.  And the trend is down on both of them, but Kinect is still  higher in current sales.  But for Total Sales, yes, the Balance board is higher.  But as you pointed out, it has been on the market twice as long.

Also, remember these numbers are inflated for the Balance Board, as many people bought the upgraded Wii Fit Plus game, who already had a Balance Board.  So the balance board numbers after 2009 are exenterated.

I think a more important question to ask about the Balance board and Kinect is; who is the biggest loser? And by that I mean which accessory helped it's users lose the most fat and get healthier.

I'd say: the lost interest in motion controls has made both obsolete. Include Wii Motion Plus and PS Move as well. To me it seems like asking: "VHS or Beta - Who will be the global winner?" instead of "Who still cares for any of them?" in 2013.

When was the last time someone here on vgchartz did an honestly enthusiastic thread raving about the terrific fun he had with the motion controls in game XY? The enthusiasm for the tech and the possibilities is over; the only kicks some people still seem to get out of motion controls is when they are mentioned in press releases with what they consider to be positive news for their favourite company.