To me, when the console that's been sold less is selling more weekly than the previous winner, then I call that "closing gap".

For example, PS3 vs Wii in Japan for last week. The gap isn't closer, as long as the Wii is selling more, even by 1 unit, that gap is still widenning.

Am I understanding the 2 words wrong?

For some "closing the gap between weekly sales" is also "closing the gap".

i dont have a single definition for that sentence. i use it in different ways. like i will say the console is closing the gap in reference to the weekly sales gap reducing. Or i will say like the console is closing the gap as in the console with the larger install base selling less then the other console with the smaller install base.

I think journalist use the term wrongly to attract attention. If you say PS3 is closing the gap with Wii then that will make people take notice and want to read the article and find out why PS3 is now able to sell more than Wii. If you say PS3 reduces weekly difference from 15,000 to 10,000 then that ain't going to interest many.

You can never close the gap unless you are selling more.

Its whatever helps the Sonyfriends sleep better.

This.

Your definition is correct.   I'm in the media and I shake my head in disbelief every time I see a headline stated incorrectly that way - usually in regards to the exact circumstances you just alluded.

If they refer to the weekly average sales gap then it should be noted as such.  An overall gap with no context to being a weekly average gap will be perceived as a total gap and any weekly unit values for Wii above PS3 by even 1 unit will still be considered a widening gap for Wii.

Unlike the "omfg, every console is down in Japan, but the xbox is UP, we are closing the gap"-comments by xbots? :)