I've got a program where I created a link tag for an email. When someone clicks on the link and goes to the webpage and fills out the form, I add them to a list based on whether the tag was present in the URL. Am I correct in thinking I can just use a trigger: fills out form on specific webpage and add a filter: opened the specific email I sent and then add them to the list? Will this do the same thing as my initial scenario? Is one way better than the other?