It could also be the last-mile part of the content you need to fix. There are many cases where the marketing part is working fine, but the sales journey is absent. High engagement with low revenue means you’re making it too hard for people to give you money. You may need to revisit your online forms, processes or perhaps the payment tool too and make them simpler.
Consider establishing a sharper call-to-action on your content as well. This might help. Instead of writing for people who want free advice, write using another angle to attract potential customers. In the content, provide a clear diagnosis, not just tips. Show them how to do it. Then add a subtle call-to-action sentences that highlight a position you are in as the expert who can save them (the customers) thousands of dollars in expenses. By having the right call-to-action, you are telling them that you are a service provider asking for their business. At the same time, they will see you as a company offering a cure to their problems.