only if you use cookies
Your site leaves a cookie behind. Whether you use that cookie and the info contained within it is irrelevant. You're still meant to give any visitor to your site the option to consent to that cookie.
That's not quite right. Lots of cookies are exempt - including the ones used in this type of industry. This is from the Information Commissioners Office website:
“In June 2012, European data protection authorities (as part of the Article 29 Working Party) adopted an opinion which clarifies that some cookie uses might be exempt from the requirement to gain consent:
Some cookies can be exempted from informed consent under certain conditions if they are not used for additional purposes. These cookies include cookies used to keep track of a user’s input when filling online forms or as a shopping card, also known as session-id cookies, multimedia player session cookies and user interface customisation cookies, eg language preference cookies to remember the language selected by the user.
First party analytics cookies are not likely to create a privacy risk if websites provide clear information about the cookies to users and privacy safeguards, eg a user friendly mechanism to opt out from any data collection and where they ensure that identifiable information is anonymised.”