Anyone NOT do it?

I've only heard of this on Hellobee, but even knowing about it for a few years now, we still haven't tried it out. Do you do this? If you do, do your kids just get the 4 things then? If you don't do it, why not?

I think we will stick with how we have been doing it with no set rules and just get some things they want, some things I think they could use, and of course books are always in there. They get a ton of books around the holidays.