I just discovered Amazon Mom. When you sign up you get three months of free Prime membership and every time you spend $25 on items in their baby department, they add another month. There are also discounts on diapers, wipes, etc for members. Just thought I'd share. :)
My best friend told me about this too--she said she tried to coordinate her free shipping months to coincide with all her holiday ordering. We don't really need that much baby stuff but I imagine we can easily come up with $25 here and there (need a new changing table pad, breast pads, etc.) and we use Amazon a lot for other stuff so I totally plan to sign up. They supposedly have good deals for signing up for regular diaper orders, etc. We're going to try to use cloth earlier than we did last time though, so probably won't use that feature. And it's not just limited to moms--anyone who cares for children can sign up (so dads, grandparents, etc.)
I've been buying diapers from amazon mom for the past year. My year of free shipping just expired (you can only earn up to 12 months of free shipping). I combined savings with subscribe and save and ended up saving 30% on 7th generation diapers (sorry this sounds like an advertisement....lol). It was really nice because I would usually get the diapers shipped and arriving the very next day.... for free! I got lucky because my son recently potty trained so I didn't need diapers anymore! I highly recommend joining.....
I use this and it's great, I order many of my home staples like toilet paper and some food items there as well. One thing to note, when you get a great deal on Subscribe & Save the shipping is free but it no longer 2 day, all regular orders still are. I guess it was just too good of a deal. Shipping is still very fast and if you are doing the subribtions it is usually easy to plan for a few extra days.