Don't spend the mental energy to try and figure out if you should be "sneaky" or not -- don't be -- be open and honest, users will remember it, appreciate it an

Don't spend the mental energy to try and figure out if you should be "sneaky" or not -- don't be -- be open and honest, users will remember it, appreciate it and if your product is valuable, your business will grow. If being sneaky with reminder emails is _what_ makes your business successful, then you are standing in quicksand.