What it means
It works best when the visitor understands the subject, likely frequency and value of the emails. The form can be part of a footer or a dedicated section. Its visual treatment should distinguish a subscription from search or a general contact request.
Use it in practice
Explain what subscribers will receive and make the submit label specific. Keep the form concise and provide a clear confirmation or next step.
Watch out for
Do not imply that entering an email does something different from subscribing. Avoid making optional details look necessary.