f5bot is a bare bones tool that is nevertheless effective at searching and monitoring for keywords on Reddit. Reddit, like all other social networks, can be tough to monitor for years on end. A lot of tools for archiving or searching it have now gone dark.
But f5bot is still going! It simply sends you an email when a new post matches your search term (and/or excludes your flagged term). And with Reddit becoming more and more mainstream (though it was pretty mainstream already), you may want to keep an eye on it for relevant news and discussions.
A few years ago, when I first wrote about Reddit for TFR, the news subreddit alone had tens of millions of potential news consumers. Check it out, reporters!