But how do you know that's an affiliate link? Ref is not always referral, could be reference as well. For example, a link I just generated in incognito (not logged in), by going to amazon.in, opening the first product I saw, clicked on share, opened the resulting link in a different browser in incognito, and it had the ref param as well.
ref=cm_sw_r_cp_mwn_dp_K9W94DMSP1TVNWXNKPDQ_1&ref_=cm_sw_r_cp_mwn_dp_K9W94DMSP1TVNWXNKPDQ_1&social_share=cm_sw_r_cp_mwn_dp_K9W94DMSP1TVNWXNKPDQ_1&language=en-IN&skipTwisterOG=1