What are Oracle-approved methods for acquiring new subscribers into my mailing list?

Environment:

Outbound Email Deliverability Best Practices
Outreach, Feedback

Resolution:

Deliverability Impact
This answer is part of the Email Deliverability Best Practices doc community. Each answer's intention is to contribute to the betterment of the email community. These answers are only related to outbound messages, and do not have any impact to the improvement of inbound deliverability. For more information regarding deliverability's role at Oracle B2C Service, please review the following answer: 
Email Deliverability Group (EDG) and Spam Considerations and Policy

Quick Look
>>  Customer acquisition methods detail the means by which a subscriber can be added to a mailing list.
>>  Consent MUST be collected from all customers in order to be messaged by a sender
>>  Oracle requires consent prior to mailing
>>  Failure to properly acquire customers can lead to reputation issues such as blocking, blocklisting, and bulking, and is a violation of global mailing requirements

Overview
Oracle recommends utilizing a closed loop confirmation or double opt in across all acquisition channels. This is the best means of determining that a contact is valid, active, and engaged in receiving content. Not utilizing this will drive hard bounces and spam complaints among new subscribers, leading to bulking, blocking, and blocklisting as a result.

Acceptable Methods 
Click to enlarge image

Closed Loop Confirmation (Double Opt-in)

• Following an initial opt-in request or action (e.g., form submit), a confirmation email is subsequently sent to notify the person that some action is necessary before his or her email address will be added to the list.
• The "double opt-in" method is considered the cleanest and highest level of permission and is especially appropriate for offline acquisition
• Users report better deliverability, open, and conversion rates
• At time of acquisition, make it clear that individual must respond to email in order to complete subscription process
• Include CAPTCHA to reduce malicious signups and blocklisting risk

Opt In

• Introduces higher level of deliverability risk as opposed to COI
• Use CAPTCHA/ reCAPTCHA on all web forms for collecting email addresses
• Requires user to take proactive steps to subscribe, therefore considered opt-IN vs the lesser opt-OUT approach
• Make it clear that checking the box means opting IN for promotional email
• Trigger welcome email (or series) for new subscribers to set expectations
• Require customer to enter their email twice to help reduce the likelihood of typos

Unchecked Box

• Separate section during the checkout process that allows customer to sign up for reward benefits
• Requires the subscriber to manually enter email address to be opted-in

Checked Box

• Pre-checked Pre-checked box presented during the checkout process
• If a visitor does not deselect the check box and submits the form they are automatically subscribed to emails
• Make it clear that a pre-checked box means that users will begin receiving email if they do not change selection (uncheck the box)
• Assumes prior business relationship
• Following up with a Welcome email is highly encouraged

Offline Opt-in

• Offline acquisition can happen at any point of customer contact, typically as part of a regular business transaction occurring in a call center or during an in-store visit or purchase
• Develop data entry plan for swift inclusion in your database for timely email triggers
• Email validation services may reduce invalid/ undeliverable addresses but they will not help avoid spam traps, spam complaints, blocklistings and blocking
• Oracle recommends confirming opt-in permission via email
• Immediately trigger a welcome or confirmation email, and personalize email with reminder/details about the opt-in source
• Do NOT incentivize sales or service personnel as that can create significant list quality and deliverability issues

Opt-In Confirm

• Marketers have a unique opportunity to acquire email subscribers through email itself
• The "primary purpose" of the email should still be deemed "transactional"
• More than two-thirds of your email content, whether text-based or graphical, must be information related to the transaction
• Recipients will not react favorably if they have to weed through copious amounts of commercial content within their transactional confirmations

Oracle Impact
Oracle is a devoted practitioner of permission-based marketing, utilizing industry best practices for all clients. The industry gold standard for collecting consent in customer acquisition is a closed loop confirmation or double/confirm opt-in. All senders MUST collect permission in order to mail on Oracle networks.

Additional References

Answer ID 1966: How do I create an Unsubscribe link to use with our mailings?

Answer ID 2674: Email address captures from "forward to a friend" links