This blog article on writing strong content marketing blog content has some examples of strong content marketing: Your Blog Content is Broken. Fix it

If you're looking for really strong examples of content marketing, the best examples are from the turn of the century: For example, the Michelin Guides (circa 1900) are one outstanding example of how far the content marketing concept can be taken, and demonstrates that great content marketing is neither spammy nor salesy. Michelin, a small French tire company, needed to get more people in cars and on the roads, so they started producing restaurant review guides. Their guides cultivated such a strong culinary following, that people started to flock to restaurants based on the guide’s rankings. Eventually, the guides helped build the reputation of Michelin’s global brand for what it is today. If one lesson can be learned from Michelin, it’s this: Solve a problem for your customers or target audience. Write posts that serve your audience.

Another example of great content marketing are those jello recipe books that were so popular in the early 1900s. They popularized jello by educating their market about how it could be made into breakfast, lunch, and dinner.