I know that survey panels like HMAC. They pay their respondents (a bit of) money for each survey they complete. And of course there are bots for that, and the s

I know that survey panels like HMAC. They pay their respondents (a bit of) money for each survey they complete. And of course there are bots for that, and the simplest strategy is to immediately call the survey panel's end point that registers a response as complete (triggering payment). That can be stopped by making the surveyor signing the link upon true completion. Just adding a key isn't going to cut it.