> I talked to a bunch of largely non-technical RSS power users and discovered that the people who really use RSS readers are subscribed to 1500+ feeds and barely scratch the surface of reading everything in them.

That is an interesting finding, in its own right. When Google neutered Google Reader's sharing features, "sharebros" started an "I am the 1000+" campaign (as a play on the "I am the 99%"). To me, that suggests having 1000+ unread feed items is common enough to be a viral joke.

There may be a business opportunity for helping people find the wheat from the chaff in their 1000+ feeds.