As a Store operator, I am not eligible for most of these free listing promotions, but like any "sale" you have to ask yourself "Cui bono?"
Who benefits?
EBay uses these promotions for two purposes. One is to encourage more listings, which looks good to their shareholders. Because eBay does not pay any dividends, their shareholders are all gamblers looking to buy low and sell the stock high. This leads to promotions that make the site look busy and profitable aroung the quarterly reports.
The other purpose is to encourage new and occasional sellers to list and perhaps sell. EBay recently invested in a lot more bandwidth, so they can afford to have 140 million listings a day or more that are not paid. They will make money when the listing sells of course. (Meanwhile , the stockholders are happy.)
As a seller I dislike all these promotions, because they flood the site with millions of listings that make my paid listings a little harder to find.
However, you should be able to list 50 auctions every month on eBaydotCA and another 50 on ebaydotCOM. (Those dotCOM listings should be different from the Canadian ones, if only because you are forced to use Flat Rate shipping instead of Calculated, but that is another discussion.)
If you keep your descriptions in a text document, preferably with HTML coding already available, and your pictures either on your desktop or in a free service like Photobucket, along with templates for your usual products, you should be able to let an unsold listing wait longer than the 90 days your Unsold List allows.
And from your Unsold List, use Sell Similar instead of Relist.