What does that mean lol?

Ah, it seems it's 3.67 after all, as of December 2014 - can't seem to find report itself (though I vividly remember seeing it in some thread around here), just this GAF thread that compiled all reports:

http://www.neogaf.com/forum/showthread.php?t=963700

Seems it just had no legs then or Nintendo stooped shipments

Nintendo overshipped at launch or rather the retailers ordered too much.
A bit uncommon but it happens here and there. Resident Evil 6 being one of those cases. They shipped over 4.5m units for launch (October), only a measly 300k more til the end of that year and only 100k more between January and March of the following year.

It's not the worst, but flopped compared to TP. Expectations were high, and the last info pointed to 4M sales, compared to the almost 8M of TP.

Yeah, it pretty much outsold Majora's Mask. And 4m cannot be considered bad by any means... it's a success. Hopefully Zelda can repeat those numbers on Wii U, which has a great attach rate.

I thought people said it was the worst 3D Zelda game, not worst selling...

if it was the former, then it is based on opinion, so that makes total sense

From what I remember, this game was incredibly front loaded in terms of sales. Like, it sold about 4 million within it's first couple months or something and then just completely fell off the map. I think it was actually out of print a year after release. This can obviously be attributed to the Wii U launching the next year. Not sure if all this is true, but I think something like this happened.

Even then they are wrong..

lol, that's not for me to decide :p