MailMerge tracks the number of recipients who clicked on any links from your email. You will be able to get the click-through rate directly on the tracking report.
'Click-through rate (CTR) is the ratio of users who click on a specific link to the number of total users who view a page, email, or advertisement. It is commonly used to measure the success of an online advertising campaign for a particular website as well as the effectiveness of email campaigns.' (Wikipedia)
After enabling the tracker and sending a mail merge, you will notice in your spreadsheet that the status will change from 'EMAIL_SENT' to 'EMAIL_CLICKED' for each email clicked (in column after the 'Merge status' column).
A note in the merge status cell will also indicate when the email has been opened, plus some additional info about WHO (email address), WHERE (ip address), DEVICE (email client, OS):
Same info you can find if you visit Your MailMerge Dashboard:
For the moment, we only track if your recipient have clicked at least once in any of the links from your emails. The click-through rate will help you measuring the success of your emailing campaigns, and should give you more useful information than the open rate only.
In the future, you might be able to get even more precisions (which link(s) have been clicked, how many times etc.) in your dashboard through the web app.
Besides, you might notice that your links have been changed in your emails, starting with 'https://dashboard.anothermailmerge.com/api/mailmerge/mail-track/link/'. This is normal, this redirection is necessary for the click tracker to work correctly.