I think you have to be a regular seller and be private.

You must not list anything using auction format or using the multi item listing - ie 1 listing that offers more than one item like "1 sold 3 available"

They only give this promo offer to selected users and I think they target private sellers that are selling high priced items via Buy-It-Now style listings in a bid to get them to lower their high prices so that they have a better chance of making a sale.

Only problem I find is after accepting this offer and using it, most of my items seem to just sit there with 0 views for up to 2-3 weeks before I get fed up and take them down and relist under the normal non promo offer where I would then get a sale on something, but if I didn't factor the MASSIVE EBAY SELLING FEES into the buy it now price then I would be selling at a HUGE LOSS !