5-door LB availability in the US

[eht13]

I wonder what the deal is with the availability of 5-door liftbacks in the US. They have been available here since the '09 model year, so the current model year is the second. But I very rarely see 5-doors out and about... every Yaris I see is either a 3-door or a sedan, about 50/50. Looking at dealer's sites out of curiosity also indicates that none or very few have 5-doors available. It seems odd given that the 5-door was introduced here for a reason... to sell more Yarises. So is the problem that low availability from Toyota has led to low sales, or that low sales has been interpreted as low demand? Toyota has the Matrix as a 5-door, plus the Scion xB and the xA/xD too... but they are also competing against the Fit, which is only a 5-door, as well as other models like the hatchback version of the Versa. So it just seems odd.