- when you upvote an item, everyone else who upvoted the item before you earns some amount of your trust
- the more of your trust someone has earned - the more weight their other upvoted items get for you
- each time they upvote, they put some amount of your trust on that item; so if you stop liking their recommendations the amount of your trust they have will go down over time
- when you downvote an item, you take away your trust from people who upvoted it; they've shown that they are not good curators of content for you, so their upvotes will have less weight for you
In this system you end up paying attention to people who have proven to you to be good curators of content. It optimizes for high signal to noise ratio, where what is signal and what is noise if up to you to decide with your upvotes. We don't have to all agree on what is globally "upvoteworthy".
There is no global reputation system (which can be gamed). Instead, there is a peer-to-peer trust system.
If you are interested in a system like that, then I would like to invite you to my hobby project that works exactly this way. Register with a temporary account (no email required) at https://linklonk.com/register and use code 'hn'.
It is early days and we don't have many users yet. To supplement real users LinkLonk supports RSS feeds as sources of information. Each feed behaves much like a user - the more you upvote content from it, the higher ranked its other entries will be for you. I hope you will find it useful and I'm looking to hear your feedback.