The system sucks, but it's the system we have, and it costs money to fight these battles. If you like the result here, consider setting up a recurring donation to the EFF.
I should do that. It would probably surpass whatever contribution I would end up giving them directly byquite a bit. I do want to support the developers though, so maybe I'll do 70% EFF, 25% devs, 5% humble tip (gotta keep the lights on).
By the time a game hits a bundle the impact on the developer's bottom line is almost negligible. If you want to support developers, buy their games when they come out. Doing otherwise is "nice," but ineffective.
It does help more than you think, being in a bundle is a big chunk of revenue for a smaller developer. While the sales do dwindle really fast after the launch, the long tail is still significant.
If games sell well early into their release, the devs would be elated and motivated. Also they would get more money at the time they are hoping to get it.
Also, when you buy a game on the Humble Store you can select which charity gets 10% of the purchase price. It gets set to some default, and it took me a long time to realise that you can change it. I have mine set to the EFF, but there are hundreds of options. The Humble Store is incidentally a great place to buy games.
Are you sure Amazon is not using smile as a pricing indicator? I.e., people who want to donate to charity maybe less price-conscious?
That's the reason I've not started using it. Online stores use all kinds of indicators (user agent, OS, number of searches for similar items, etc) to jack up prices when they think they can get away with it, and I suspect this metric is very relevant in that context.