My sister does this every year. Her previous partner (who thankfully is no longer around) made sure that there were never any savings left after each payday so saving was impossible. She has 3 kids and is a SAHM so she is happy to stay home for delivery.

To my sister it guaranteed treats for Christmas as well as the basics and the booze.

She just got her deliveries for this year. Don't know why they are so early, but they always seem to be.

She currently has about 17 boxes worth of stuff which she is sorting through and giving some to family as she really doesn't need 17 bottles of cordial and 12 boxes of chips. However, it will last them for a while.

Personally, I wouldn't do it as it is so very expensive but if you are on limited income and can't save for whatever reason, it seems to work well.