From my experience, anything that sells is covered, regardless of listing date.

However, the account that I get that promo on has little listed since they stopped offering the 3 day unlimited freebies, and most aren't there for long. The first $0 FVF I got with the current promo was listed on 15 Feb. The promo started on 17 Feb.

No guarantees, simply what I have found. As they aren't extra listings, I just list what I normally would and if they sell fee-free, it's a bonus.

Ta. 

forget that offer.  ive had that offer 4 times and EACH time i go to use it they charge me $1.65 insertion fee.   EACH time i go on chat they are hopeless and have no idea.  My other ids have the same promotion and yes all those i get charged as well.  Its a problem they say but nothing ever gets fixed

Realise that they are only FVF free. Not hard, if you've actually read the thread, rather than repeating what you've already posted on another one.

And it wasn't an offer, per se, it was automatically activated.