Programs: Hilton & SPG Gold, & every airline program that I can join
The only thing listed on www.rewardsdb.com is rebates for UK sites. There is a thread here about a 10% donation to Amnesty Intl, but as I mentioned in the earlier thread, I usually go to the rewardsdb.com site to link there to thank Andrew Cram for all the work he has done on that site for all the other miles earning info.
Between he, PGary, and FT we have earned many, many miles!
Although its not listed on shop4miles' site as worth anything (it says 0 miles per dollar), a polite email to the customer service usually results in them offering one mile per dollar for Amazon.com. Think of it as an unadvertised bonus.
I just bought a few orders of books and by simply asking in this manner, I've been awarded 1 mile per dollar at Amazon for all those purchases.
Programs: HHonors Gold, Priority Club Plat, AAdvantage, Delta Skymiles, others including Amtrak Guest Rewards
For book purchases, I've gone through their partner site, Target, and gotten miles/points -- SOMETIMES. Some portals work, some don't. I figure if it works, it's also an unadvertised bonus One portal specifically says Amazon purchases excluded, so I have never tried that one...lol
At one point, with Citibank (Diamond Preferred Rewards) you could buy Amazon.com gift certificates and get 5% back. I don't remember whether that was on top of the 1% you'd get for regular purchases.
Anyway, if you have an Amazon.com credit card you can get 3% back. I'm pretty sure the details/links to apply are available from the Amazon.com site.
It may only give you gift certificates towards future purchases; don't remember.