I had an idea similar to this as well - to help people kickstart recommendations for their friends. I'm thinking of creating a personal url for each user (e.g.,

I had an idea similar to this as well - to help people kickstart recommendations for their friends. I'm thinking of creating a personal url for each user (e.g., linklonk.com/u/lonk). If someone upvotes that url - they establish connections to the sources that user is connected to. When you want to introduce someone to LinkLonk you could share with them your personal url. As for decaying sellouts, wouldn't downvoting the content they upvoted do what you want? By the way, every time someone you are connected to upvotes something, your connection to them becomes slightly weaker. So if you simply ignore recommendations from sources with a lower signal-to-noise ratio (or high volume) - their recommendations will eventually fade away from the "For you" page.