I subscribe to a lot of RSS feeds and this creates a data overload problem. There are feeds I do not want to stop watching, but contain many items I am not interested in reading. I can skip over them but I would prefer not to see them at all.
The answer is a feed reader with filters. A good filtering system can hide unwanted items. Unfortunately, only one online feed reader provides filters. Google Reader does not provide them. Neither does Fastladder or Bloglines.
NewsBlur is the only online feed reader than provides filters and I now use it for many of my feeds. NewsBlur, for some unknown reason, calls its filtering system the Intelligence Trainer. This is rather foolish since it obscures that they are actually providing a good feed filtering system. Not sure why they would want to hide their unique selling point.
Newsblur only offers kill filters. They work on words in the post title, author and tags [but not in the body of a post]. It does not provide watch filters. These search posts for keywords in title, author, tags and body.
A desktop feed reader called Blogbridge is the only reader that I am aware of that provides both kill and watch filters, but they are not well implemented.