email,fb_id,google_click_id,platform,first_seen,last_seen audience1@example.com,fb_77881122,,facebook,2026-01-05,2026-04-20 audience1@example.com,,gclid_AAA111,google_ads,2026-02-10,2026-04-18 audience1@example.com,,,organic_form,2026-03-15,2026-03-15 audience2@example.com,fb_99887766,,facebook,2026-02-01,2026-04-15 audience2@example.com,,gclid_BBB222,google_ads,2026-02-20,2026-04-22 old.email@example.com,fb_55443322,,facebook,2025-06-10,2025-12-01 new.email@example.com,fb_55443322,,facebook,2026-01-15,2026-04-20 ,fb_11223344,,facebook,2026-03-01,2026-04-01 ,,gclid_CCC333,google_ads,2026-03-10,2026-04-10 fbonly@example.com,fb_44556677,,facebook,2026-03-20,2026-04-20 googleonly@example.com,,gclid_DDD444,google_ads,2026-03-25,2026-04-22 organiconly@example.com,,,organic_form,2026-04-01,2026-04-01 combined@example.com,fb_88990011,gclid_EEE555,manual_merge,2026-04-10,2026-04-25 ,,,sms_list,2026-04-05,2026-04-05