Users click on hyperlinks in unpredictable ways. For example, they might not click on a link within a solo email message or an ad within a newsletter for many months after the time of transmission.
This means you should look at the response rates long after transmission. No need to obsessively watch them daily or weekly if the message went out months prior. But, do check in to see the increased number.
People will save an appealing offer. Or, they might bookmark the landing page for when they have more time. If you held a real-time Webinar, put a link to that event’s archive on your landing page for latecomers. LC