This saying means as much online as it does in real life. If you have nothing to say, keep quiet. There’s nothing worse than finding the search results filled up with waffle, especially when you’re trying to find some useful information in answer to a query.
Luckily Google is fairly good at weeding out the wheat from the chaff, and if a website is filled with gibberish it tends not to rank anyway. Therefore, if you add rubbish to your website you’ll be doing it a disservice.
The reason we mention this is that most people know by now that websites with regularly added content rank better in the SERPs, that’s why content providers are able to sell content to clients. However, that content needs to be intelligent, useful and relevant to the client’s website. If it’s irrelevant, it won’t help the rankings of the site at all. It will have the opposite effect, causing the rankings to suffer.
So, if you want to add content to your website make sure it’s relevant, well written and interesting. Don’t add content for the sake of it, you’ll find it has the opposite effect than you were hoping for.