Aggregating content from multiple sources is the role of media and reference websites. If you blog to market your services or display thought leadership, you need to create original content relevant to your target audience.
Your insights and reflections are what differentiate you from others and attract followers, clicks and shares. They also are the stuff that incites engagement.
To engage customers or constituents, you need to be engaged with your subject. Talk about what you know, what you feel, what you believe. Share your experiences. Be the expert people are looking to find.
Borrowing and circulating what someone else knows, feels or believes is akin to advertising your competitors. It's fine to quote a source that inspires or informs your thought, but why rehash someone else's work at the expense of sharing your own?
Content curation is in vogue and serves valuable purposes. But one of them isn't distinguishing you. It is okay to supplement your original content with links to related stories and information. That conveys a sense of command and breadth of awareness of your subject, which enhances your reputation — the very point of a marketing blog.
Creating original content takes time, but it is worth the effort and care.
Original content extends beyond first-person commentaries. You can originate and package content from credible third parties or your customers. You can demonstrate the range of opinion by contrasting prominent views or show why you take issue with another viewpoint.
The successful marketing blog connects you and your audience by sharing what you know with what they want.
If your original content reflects your core brand, it will reveal why you are special.