This issue has been bothering me as I can't quite yet quit Amazon. We have only ordered a few things the past few months but there is no easy solution to replace. Unfortunately one would need to register with a plethora of other online retail sites to replace the amazon 'one source'. We have ordered some vitamins and supplements from local health food stores as one alternative for our needs. Also some e-bay orders as they have more diverse ownership / decentralized.
I quit Facebook 2-3 years ago and am committed to quitting Amazon. Maybe in 5-10 years we can have the new, decentralized "one source" for online retail?
peace 
