The 10 items I found have all been corrected.

When I was in retail sales, we had an average of 3-4 errors in the newspaper per week. (we were a major national chain store listing hundreds of items) We were not required to honor errors in the ad. We posted a corrected letter of apology from the printer in each store.
I personally would assume it was a typo because the item isn't really free. Why would they be in business to sell free merchandise?