E-commerce tracking exists so that you can measure the success of your email marketing efforts. When a subscriber opens an email, clicks on your e-commerce block and is redirected to your website where they make a purchase—that purchase is recorded in your campaign report.
Purchases are always recorded in the campaign report from the last campaign the subscriber clicked before making their purchase. We then track data for 30 days after the last visit from an email campaign.
Cookies are not used to track your subscribers activity in your store, visits and purchases are saved to your MailerLite account in the same way opens/clicks are.