That’s because minimum spends might… apply.
To cut a long story short - some media owners are not comfortable with their boards being a free-for-all. And this is for good reason; they often have a lot of boards on their network and it’s a bit of an administrative nightmare to approve the thousands of artworks that get submitted to them everyday.
Their solution to this problem is to apply a minimum spend. By saying that advertisers must spend some kind of minimum amount before getting access to their boards, they effectively lower the amount of admin work they’ll have to do.
Most media owners are quite reasonable about their minimum spends, though. If you do notice a minimum spend warning in platform that looks like this:
Please do reach out to the team!
Chances are, you’re probably spending enough to get over the minimum spend anyway and you can freely add those boards into your campaign.