I hate to say this, but the startup graveyard has a really huge section filled with every company who has tried to do this kind of thing. you feel like there should be a way to improve on something that people are already passionate about, and that would naturally lead to high adoption. But, a lot of great attempts have just never gotten peoples' attention.

What's more, all the things that obviously would make money are probably already saturated by something that Amazon does.

It's a real shame.