Sometimes these little boxes are to be checked if you DON’T want to make monthly donation payments. And they are generally overlooked.
The Hearst Corporation uses this trick for their magazine subscriptions.
This is a trick that has been taken up by a lot of online sellers. I used to buy an over the counter supplement which seemed to work as advertised but you could not order online without being placed on an automatic reorder schedule and then they would ship twice a month rather than monthly. After talking on the phone with them and still having the same problem I stopped using their product. Sometimes greed backfires.