Newsletter marketing is an effective way to reach and engage your audience. They can be a great source of information and content, and can help to create a relationship with your customers.
However, newsletters are not always accurate or reliable. They can be full of outdated information, or contain advertisements that may not be relevant to your audience.
Additionally, newsletters may only be sent to a certain subset of your audience, which could limit their effectiveness.
Ultimately, whether or not newsletters are a good source of information depends on the quality of the content, the accuracy of the information, and the relevance of the ads.