we've had two clients ask about limiting completions by a UID vs. a user session. Currently we have a variety of workarounds to limit completions while still maintaining a good user experience. The option to use UID for known users seems like an interesting one for those coming through email or via app. Both Pepsi and Fetch have asked about this.
Fetch - standard survey use case. only want users to go through once
Pepsi - sweepstakes launching via app
