When will it be time to stop tracking Vita?

[Medisti]

killeryoshis said:

Medisti said:

I didn't realize that, but weren't those selling better?

Check for yourself 
http://www.vgchartz.com/weekly/42932/Global/

The Vita is selling better than both of them in that link. 360 is below 1k.

So, the time to stop tracking when the baseline falls to 1-2k?