Normally I would agree with both of these because they seem to be the reasons other companies introduce currency schemes. But in this case I think it's telling that Amazon first made the announcement on a blog for app developers. My guess is they are trying to attract developers by guaranteeing them a market.

If you're interested, I wrote about it in IEEE Spectrum when they first announced Amazon Coins in February.

http://spectrum.ieee.org/tech-talk/telecom/internet/amazon-c...