Monday is feeding day here. Though recently I've been toying with the idea of feeding every 4 days or so. Mainly because, we get a lot of refusals when offering prey that is approx 15% of the weight of the snake. We have some snakes that just seem flat-out intimidated by the size of the prey. So I was thinking of feeding smaller meals, more frequently.
I've spoke with a few breeders in my area who also feed this way, with great success. While I don't think a 3 day schedule is going to do any harm, you just need to make sure the size of the prey is appropriate. Obviously you're not going to be feeding the snake 30% of it's weight within a week, that's crazy.