I recently came across this external blog post by Courtney Grimes and thought it would be useful to share with the community (great post, btw, Courtney). Especially since there has been a lot of discussion/questions recently on false-positives of email opens and clicks:
I did want to comment on the guidance to combat this:
After testing this idea on dozens of different Marketo instances, the single most effective way I’ve found to track email clicks is a combination of two filters: Email was delivered + Visited web page: [web page linked to in email]
Typically, one would simply add these two filters to the smart list of the trigger campaign. When we tried that in the past, it didn't work for us since Marketo doesn't log this activity immediately as it happens - at least not in our case (especially the "visited web page" activity). We've seen up to a 45 minute delay. So we used an alternate approach: we included a "visited web page" choice in our "change program status" flow step. And prior to that flow step, we also included a 45 minute wait step. The only issue with this approach is if the user ever visited this page in the past, the choice will still be true. In other words, the choice step is not directly tied to this instance of the email click.
As Courtney states in her wrap-up, there really is no fool-proof solution. But if you had to pick one, this is probably the best approach.