A lot of people set up a Google Alert for their company name, see that it covers "the web," and assume that includes Reddit. Then they go quiet for months and figure nobody is talking about them. Usually that is not true. People are talking. Google Alerts just is not catching it.
If you want to know what gets said about you on Reddit, Google Alerts is the wrong tool. Here is why, and what to use instead.
Two reasons.
First, timing. Google crawls Reddit on its own schedule, and it is not in a hurry. A thread can come and go before Google ever indexes it. Most Reddit conversations are over in a day, so "eventually" ends up being the same as "never" for this.
Second, and this is the bigger one: comments. Google Alerts will sometimes pick up a Reddit post, the top-level submission with a title. It almost never picks up the comments. On Reddit, the comments are the conversation. Someone posts "what does everyone use for X," and the answers are all down in the replies, exactly where Google Alerts does not look.
None of this is Google's fault. Google Alerts is built for the open web: news sites, blogs, and the like. Reddit is a different kind of place, with most of the content sitting several levels deep in comment threads, which Alerts simply does not reach.
You want something that reads Reddit directly, looks at both posts and comments, and tells you when your keyword shows up. That is what F5Bot does.
F5Bot is a free service that pulls new Reddit posts and comments, checks them for the keywords you set, and emails you when there is a match, with a link straight to it. It does the same for Hacker News and other sites while it is at it.
Google Alerts is still fine for what it is good at. If you want to know when a news site or a blog mentions you, keep your Google Alert running. The two tools cover different ground. Keep Google Alerts on the open web and let F5Bot handle Reddit and the other forums. There is no reason to pick just one.
It is about a minute of work. Make an account, add your company or product name as a keyword, and you will start getting emails when it comes up. Adding your domain as a keyword is a good idea too, so you catch it when someone links to you.
If you want the longer version, with tips on misspellings and cutting down on false positives, see the brand mention guide.
A note on plans. F5Bot's free plan works, with some limits: alerts go out on a delay, the most common keywords are off the table, and there is a daily cap on matches per keyword. F5Bot's paid plans send alerts in a timely manner, raise the caps, open up the common keywords, and add the include and exclude filters for trimming down noise. The top tiers even add F5Bot's AI-powered filtering, which judges each match by what it means instead of the exact words. You can read about that on the semantic alerts page, and compare plans on the pricing page.
If Google Alerts has been quiet, this is probably why. Set up a free account and see what you have been missing.