Currently making my own social network from scratch and it's more media-based than text-based, but I love the idea of RSS feeds for everything. My only concern would be extra bandwidth requirements if there's a ton of readers out there constantly fetching updates.

It's better than someone F5-ing a page and redownloading all the assets, but feed readers check automatically on a (usually short) timer, so it's not really comparable.

Does YouTube still offer RSS feeds? I remember those being extremely useful when they swtiched from reverse-chronological to the recommendation-driven Home feed.