I am exploring the best UX solution for newsletter checkbox (i.e. newsletter signup) for social sign on (SSO - sign up with Google, Facebook, Apple etc).
The problem: SSO are required to have middle step where the actual decision of signup/login is on a third party. Newsletter signup, by law in some countries, require an action of confirmation (checkbox, email input, etc) but it cannot be moved to the SSO screen.
Solutions I can think of:
- Add extra step to SSO flow. Disadvantage: I don't need to ask anything else besides the newsletter, it's irritating users with extra step.
- Ask for newsletter signup before clicking the SSO button. Disadvantage: confusing since (for example, Google) button is very recognizable action and checkbox will be missed. Also I cannot make it required, so customers will likely skip it.
- Ask for newsletter signup after login via a banner or popup. This is what I'm currently doing on startnew.app, it's a small popup but attracts the eyes (I can tell by heatmaps)
What do you think is best and why? Am I missing some other way?