Some indicators of effective content marketing include:
Higher open rates and/or click rates can indicate effective email content encouraging users to read and click through. If your subscriber list is growing over time, this is also a good sign.
Metrics like pages per session, average time on page, new/returning traffic, and goal conversions are worth tracking. The more engaged users are, the more effective your content marketing is likely to be. Growth in traffic sources (such as organic traffic, referral traffic, and social media traffic) can be a sign of effective content marketing, as is overall audience growth.
On social media channels, there are many metrics you can track to gauge the effectiveness of your content marketing. Reach is a measure of how many people are seeing your content. Follower growth doesn’t always correlate with higher reach, but it can be a sign of effectiveness. Engagements such as likes, shares, and comments are the biggest indicators of effective content marketing.