Clicking tracked links doesn't result in being cookied
I am referring to the anonymous IP address field to see if someone has been coockied.
We recently re-synced our CRM with marketo, and in order to obtain as much cookies as possible we have sent a series of mails.
The number of people that clicked one of the tracked emails is significantly higher than the number of people with a value for anonymous IP.
See the attached screenshot of the people that clicked a tracked link in the email, only 1 has a value for anonymous IP.

What is the reason for this ? How do you count your cookied contacts