Pinterest automatically adds the query string parameters pp=0 and pp=1 to the destination URL of a Pinterest ad. You can use them to distinguish between first-order traffic and downstream traffic on your ads. You can also use them to track standard ad activity in Google Analytics.
pp=0 indicates paid clicks, caused by first-order traffic. This means that someone clicked a standard ad and ended up on your site.
pp=1 indicates earned (unpaid) clicks, caused by downstream traffic. This means that someone clicked your standard ad after it had been saved to a board, and ended up on your site.
If you're having issues with the PP query string parameter and would like to opt out, please