Unfortunately, there are times when the system retroactively presents offers that may have been made before, but are actually not supposed to be made available to users within a certain demographic. In other times, some offers are simply outside of the geographical scope of our advertisers.
It wouldn't do much for a bikini company to try and sell their products to a user who is from the North Pole.
Another reason for this may be upon the request of our sponsors to exclude participants based on a certain criteria that does not match with the market demographic. In the world of advertising, specific targeting means lower ad spends per capita. The better you are at selling exactly what you want to sell, to the right people, the lower your costs are in paying for advertisements. Sometimes we have to manually create overrides when the system makes a mistake.