A business blog is the most common form content marketing takes, and also the most commonly wasted. The difference between one that works and one that does not is almost entirely a question of who it is written for.
A business blog exists to answer the questions your potential customers have before they are ready to buy. Every article should be findable by someone searching for a problem you can help with.
It is not a company news feed. Announcements of office moves, staff birthdays, and anniversary celebrations serve the business, not the reader — nobody searches for them, and they attract nobody.
The clearest sign of a blog written for the wrong audience: every post begins "We are pleased to announce". Those posts do no harm, but they also do nothing, and they consume exactly the effort that could have gone into something a stranger might find.
The instinct is to present your service as right for everyone. Content that admits limitations — who this is not for, when a cheaper option is fine, what you are not good at — is consistently more persuasive, because it is obviously not just sales copy. It also filters out enquiries that were never going to work out, which saves everyone time.
An old post that still ranks and still brings readers is a real asset, and it decays if the information in it goes out of date. Revisiting the handful of posts that actually get traffic — checking facts, updating anything stale, improving what is thin — is usually a better use of an hour than writing something new.
This is the same argument the SEO course makes about content freshness, and it is worth acting on because almost nobody does.