What is an opt-in?

The term ‘opt-in’ is used across the digital marketing industry for the process of gaining user consent within a range of contexts. In mobile marketing, opt-in generally refers to the process where users voluntarily agree to receive marketing communications, push notifications, personalized advertising and app services, and targeted advertising—including retargeting. Opting-in, or providing consent, usually involves an explicit action, like checking a box, signing up via a form, or agreeing to an app’s terms and conditions. In the case of Apple’s App Tracking Transparency (ATT), with which the term ‘opt-in’ has become synonymous, users can select “Allow Tracking” to opt-in or “Ask App Not To Track” to remain opted-out.

Opt-in practices ensure compliance with privacy regulations and build trust with users by allowing them to control the type and frequency of the communications and advertising they receive. Brands and apps that succeed in communicating the value of opting-in to users typically see enhanced consent rates and better user engagement. This is thanks to more granular data and increased permissions, which enable a personalized user journey.

Some examples where marketers need opt-ins to access and store specific information or communicate with users for advertising purposes include:

• SMS marketing
• Push notifications
• Newsletter subscriptions
• Email marketing
• Cookies
• App Tracking Transparency (ATT)
• Location services
• Google’s GAID

Opt-ins are required to ensure that marketing practices comply with privacy laws, rules, regulations, and frameworks. Examples include laws like the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) as well as frameworks like ATT. These regulations mandate that users must explicitly consent to any data collection or marketing communications. Specific to mobile, opt-ins are required to share device identifiers, which are commonly used for attribution and personalized targeting.

Apple’s ATT, which governs access to the identifier for advertisers (IDFA), spearheaded an industry-wide, privacy-first shift in mobile advertising. Starting from iOS 14.5, users must opt-in to share their IDFA. Similarly, Google currently allows users to configure their Google Advertising ID (GAID) and privacy choices in their device settings, effectively opting-out of data sharing. The expectation is that with the rollout of Google’s Privacy Sandbox on Android, access to the GAID will be further reduced, or reliance will be decreased in favor of the new, privacy-centric framework.

A double opt-in is an additional layer of verification used in the opt-in process to ensure the authenticity and intent of the user’s consent. When a user initially signs up or consents to receive communication or share their data, if a double opt-in is triggered, they will receive confirmation email or message. From here, they must confirm their opt-in by clicking on a link or responding to the message. This two-step process helps verify that the user’s information is valid and that they genuinely want to opt-in to what they initially agreed to/clicked/approved.

This process does reduce the total number of opt-ins to any initiative, but also reduces the likelihood of spam while enhancing the quality of the subscriber list or database. There are several countries where a double opt-in is legally required to store and process the data gathered. These countries include: Austria, Germany, Greece, Luxembourg, Norway, and Switzerland.

Introduced by Apple in 2021, ATT is a framework that requires mobile apps to obtain user permission to access their personal device identifier. Access to the IDFA enables tracking of activity across other apps and websites, which facilitates highly targeted advertising, campaign optimization, and attribution.

When a user installs or opens an app for the first time after the ATT framework is implemented, they are presented with a prompt giving them the option to allow or deny tracking. If the user consents, the app is granted access to the IDFA, enabling them to measure performance and deliver personalized ads. If the user denies permission, the app cannot access the IDFA, and must perform attribution via Apple’s SKAdNetwork (SKAN) or AdAttributionKit. This opt-in process ensures that users have control over their data and can make informed decisions about their privacy preferences.

To increase opt-in rates for any channel or campaign type, the best practice is to make the process as seamless and appealing as possible.

• Clear value proposition: Clearly communicate the benefits users will receive by opting in, such as exclusive content, personalized offers, enhanced app functionality, more relevant ads, or even less ads.
• Simplify the process: Reduce the number of steps required to opt-in (where possible/compliant) and make the process intuitive from a UX perspective.
• Timing and context: Ask for opt-ins at moments when users are most engaged, such as after completing a task or experiencing a popular feature. Many apps build their relevant opt-ins into specific parts of the onboarding process.
• Transparency: Be transparent about what data will be collected and how it will be used, reassuring users of their privacy and data security. Apple’s Privacy Nutrition Labels require apps to provide all of this information, making the framework a useful way to understand what needs to be clarified, and why.
• Incentives: Test offering incentives such as discounts, free trials, or access to premium features as a way to encourage users to opt-in.
• A/B testing: As with all marketing strategies, an A/B test goes a long way in determining what yields the best results for your different segments. You may find that different user personas opt-in at higher rates following different flows and prompts.

In terms of the ATT opt-in, you can read our series on getting the opt-in and design do’s and don'ts for increasing consent rates here. For the latest ATT opt-in rates across verticals and regions, check out Mobile app trends 2024 edition: A global benchmark of app performance.

For more information on opt-ins, scaling your app growth amid evolving privacy rules and regulations, working with SKAN and AdAttributionKit, and more, reach out to your Adjust contact person or request a demo today.